{"id":118,"date":"2019-05-06T19:38:37","date_gmt":"2019-05-06T16:38:37","guid":{"rendered":"http:\/\/mathwithoutborders.bg\/public_html\/en\/?page_id=118"},"modified":"2019-05-07T12:36:39","modified_gmt":"2019-05-07T09:36:39","slug":"lyubomir-lyubenov","status":"publish","type":"page","link":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/lyubomir-lyubenov\/","title":{"rendered":"Lyubomir Lyubenov"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"118\" class=\"elementor elementor-118\">\n\t\t\t\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-310c991 elementor-section-full_width elementor-section-height-min-height elementor-section-height-default elementor-section-items-middle\" data-id=\"310c991\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;,&quot;animation&quot;:&quot;none&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-no\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-cad4c43\" data-id=\"cad4c43\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-2f8739a elementor-widget elementor-widget-text-editor\" data-id=\"2f8739a\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.8.0 - 30-10-2022 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#818a91;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#818a91;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<p><a href=\"http:\/\/mathwithoutborders.bg\">\u00a0\u00a0\u00a0<\/a><a href=\"http:\/\/www.mathwithoutborders.bg\/index.php\/lubenov\/\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-147\" src=\"http:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/BG.jpg\" alt=\"\u0411\u044a;\u0433\u0430\u0440\u0441\u043a\u0438\" width=\"30\" height=\"20\" \/>\u00a0\u00a0\u00a0<\/a> <a href=\"http:\/\/mathwithoutborders.bg\/public_html\/ru\/index.php\/lyubomir-lyubenov\/\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-149\" src=\"http:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/RU.jpg\" alt=\"\u0420\u0443\u0441\u043a\u0438\" width=\"30\" height=\"20\" \/><\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-e615c4d elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"e615c4d\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-9e10c5e\" data-id=\"9e10c5e\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-d75e535 elementor-widget elementor-widget-heading\" data-id=\"d75e535\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.8.0 - 30-10-2022 *\/\n.elementor-heading-title{padding:0;margin:0;line-height:1}.elementor-widget-heading .elementor-heading-title[class*=elementor-size-]>a{color:inherit;font-size:inherit;line-height:inherit}.elementor-widget-heading .elementor-heading-title.elementor-size-small{font-size:15px}.elementor-widget-heading .elementor-heading-title.elementor-size-medium{font-size:19px}.elementor-widget-heading .elementor-heading-title.elementor-size-large{font-size:29px}.elementor-widget-heading .elementor-heading-title.elementor-size-xl{font-size:39px}.elementor-widget-heading .elementor-heading-title.elementor-size-xxl{font-size:59px}<\/style><h2 class=\"elementor-heading-title elementor-size-large\">Lyubomir Lyubenov<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-3cd2ce0 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"3cd2ce0\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-5e05b3d\" data-id=\"5e05b3d\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-5193e06 elementor-widget elementor-widget-image\" data-id=\"5193e06\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.8.0 - 30-10-2022 *\/\n.elementor-widget-image{text-align:center}.elementor-widget-image a{display:inline-block}.elementor-widget-image a img[src$=\".svg\"]{width:48px}.elementor-widget-image img{vertical-align:middle;display:inline-block}<\/style>\t\t\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"257\" height=\"300\" src=\"https:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/Lubenov-257x300.jpg\" class=\"attachment-medium size-medium\" alt=\"\" srcset=\"https:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/Lubenov-257x300.jpg 257w, https:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/Lubenov-230x268.jpg 230w, https:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/Lubenov-350x408.jpg 350w, https:\/\/mathwithoutborders.bg\/public_html\/en\/wp-content\/uploads\/2019\/05\/Lubenov.jpg 446w\" sizes=\"(max-width: 257px) 100vw, 257px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-1fc1746 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"1fc1746\" data-element_type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-2db7573\" data-id=\"2db7573\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-0f1b967 elementor-widget elementor-widget-text-editor\" data-id=\"0f1b967\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div id=\"main\"><div id=\"site_content\"><div class=\"content\"><p>Mathematics teacher.<\/p><p>Born on 6th March 1960. Graduated from Plovdiv University in 1981.<br \/>Worked as a mathematics teacher in secondary and higher education, and also in the state administration of Bulgaria from 2002 until 2012.<br \/>Founder of the international mathematics tournament &#8222;Drouzhba&#8220; (\u201e Mathematics Competitions \u201d &#8211; &#8222;Drouzhba&#8220; Mathematical Contest , pp. 10-14, Vol 3, No 2, 199 0; Kvant, 1991 \u0433.), during which was held the first mathematical linguistics competition in the world, in 1988. (Stara Zagora)<br \/>Member of the &#8222;International mathematics tournament of towns&#8220; organisers committee.<br \/>Author of three articles, published in the magazine &#8222;Mathematics Competitions&#8220; of the World Federation of National Mathematics Competitions . (WFNMC) in 1990, 1998 \u0438 2001 ( Ingenious Solutions to Competition Problems , pp. 75-85, Vol 14, No 1, 2001; Mathematics Competitions under the Aegis of a Newspaper , pp. 20-35, Vol 11, No 1, 1998; &#8222;Drouzhba&#8220; Mathematical Contest , pp. 10-14, Vol 3, No 2, 199 0 ).<br \/>Publisher of the &#8222;Mathematics post&#8220; newspaper. (1991-2004)<br \/>Author of mathematical problems and articles, published in issues in Canada, Singapore, Germany, Poland, Romania, Russia and Australia.<br \/><br \/><strong>List of articles by Lyubomir Lyubenov <\/strong><br \/><strong>Mathematics Competitions (Australia) <\/strong><br \/>This Journal is published by AMT Publishing (with significant assistance from the UK Mathematics Trust) on behalf of theWorld Federation of National Mathematics Competitions.<br \/>2001 Vol 14 \u2116 1<br \/>Lyubomir Lyubenov, Ingenious Solutions to Competition Problems, pp. 75-85<br \/>1998 Vol 11 \u2116 1<br \/>Lyubomir Lyubenov, Mathematics Competitions under the Aegis of a Newspaper, pp. 20-35.<br \/>1990 Vol 3 \u2116 2<br \/>LT Lyubenov, &#8222;Drouzhba&#8220; Mathematical Contest, pp. 10-14.<br \/><br \/><strong>Die WURZEL (Germany)<\/strong><\/p><p>Zeitschrift f\u00fcr Mathematik<br \/>Heft 12\/1992: Eine Sammlung von quadratischen Trinomen \u2013 seite 292- 295<br \/>Heft 1\/1994: Die Methode der trennenden Konstanten \u2013 seite 10 \u2013 15<br \/>Heft 6\/1994: L\u00f6sen von Aufgaben durch Bildung vollst\u00e4ndiger Quadrate- seite 114<br \/>Heft 6\/2001: Die 180-j\u00e4hrige Ungleichung \u2013 seite 135<br \/>Heft 2\/2013: Gedanken zu einer Aufgabe des bulgarischen K\u00e4nguru-Wettbewerbs \u2013 seite 43- 46<br \/>Heft 6\/2013: Quadratische Ungleichungen \u2013 seite 120-123<br \/><br \/><strong>Die Alpha (Germany) <\/strong><br \/>Zeitschrift f\u00fcr Mathematik<br \/>Heft 2\/1991: Wie uns die Einerziffer helfen kann- seite 38<br \/>Heft 5\/1994: Nicht immer zum Computer grefen!- seite 14<br \/><br \/><strong>Mathematics and Informatics quarterly ( Singapore)<\/strong>;<br \/>Warm Ups \u2013 Richard Palmaccio &amp; L. Lyubenov, vol. 11, 1\/2001<br \/>A Triangle Inequality \u2013 Jim Boid &amp; L. Lyubenov, vol. 11, 3\/2001<br \/><br \/>\u00a0<\/p><p><strong>\u0441\u043f. \u041c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430 <\/strong><strong>\u0438 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0442\u0438\u043a\u0430<\/strong><strong> (Bulgaria)<\/strong><\/p><p>L. Lyubenov, R. Mavrova &#8211; Solving Some Problems by Completing the Square, 6, 1993<\/p><p><strong>L. Lyubenov &#8211; <\/strong>4 th International Mathematics Tournament \u201cDrujba 90\u201d, 3, 1991<\/p><p>\u041b. \u041b\u044e\u0431\u0435\u043d\u043e\u0432, \u041f\u0435\u0442\u0438 \u043c\u0435\u0436\u0434\u0443\u043d\u0430\u0440\u043e\u0434\u0435\u043d \u043a\u043e\u043d\u043a\u0443\u0440\u0441 \u043f\u043e \u043c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430 \u201e\u0414\u0440\u0443\u0436\u0431\u0430 91\u201c, \u0431\u0440. 5, 1991<\/p><p>\u041b. \u041b\u044e\u0431\u0435\u043d\u043e\u0432, \u0427\u0435\u0442\u0432\u044a\u0440\u0442\u0438 \u043c\u0435\u0436\u0434\u0443\u043d\u0430\u0440\u043e\u0434\u0435\u043d \u0442\u0443\u0440\u043d\u0438\u0440 \u043f\u043e \u043c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430 \u201e\u0414\u0440\u0443\u0436\u0431\u0430 91\u201c, \u0431\u0440. 5, 1991<\/p><p><strong>\u041b. \u041b\u044e\u0431\u0435\u043d\u043e\u0432, <\/strong>\u0415\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u043e \u043f\u0440\u0438\u043b\u043e\u0436\u0435\u043d\u0438\u0435 \u043d\u0430 \u0435\u0434\u043d\u0430 \u0444\u043e\u0440\u043c\u0443\u043b\u0430, \u0431\u0440. 4, 1988<\/p><p><strong>L. Lyubenov &#8211; <\/strong>The Tried International Mathematics Tournament \u201cDrujba 89\u201d, 4, 1990<\/p><p>\u00a0<\/p><p><strong>\u0441\u043f. \u041c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430 (Bulgaria) <\/strong><br \/>1981<br \/>\u041c\u0435\u0442\u043e\u0434\u044a\u0442 \u043d\u0430 \u043a\u043e\u043e\u0440\u0434\u0438\u043d\u0430\u0442\u0438\u0442\u0435, \u0431\u0440\u043e\u0439 7, 1981 \u0433.<br \/>1986<br \/>\u041e\u0431\u043e\u0431\u0449\u0435\u043d\u0438\u0435 \u043d\u0430 \u0435\u0434\u043d\u0430 \u043a\u043e\u043d\u043a\u0443\u0440\u0441\u043d\u0430 \u0437\u0430\u0434\u0430\u0447\u0430, \u0431\u0440\u043e\u0439 1, 1986 \u0433.<br \/>1987<br \/>\u041a\u0430\u043a \u043c\u043e\u0436\u0435 \u0434\u0430 \u043d\u0438 \u043f\u043e\u043c\u043e\u0433\u043d\u0435 \u0446\u0438\u0444\u0440\u0430\u0442\u0430 \u043d\u0430 \u0435\u0434\u0438\u043d\u0438\u0446\u0438\u0442\u0435, \u0431\u0440\u043e\u0439 4 \u0438 \u0431\u0440\u043e\u0439 5, 1987 \u0433.<br \/>1989<br \/>\u041a\u043e\u0440\u0435\u043d \u043f\u043e\u0434 \u043a\u043e\u0440\u0435\u043d\u0430, \u0431\u0440\u043e\u0439 2, 1989 \u0433.<br \/>1992<br \/>\u041d\u044f\u043a\u043e\u043b\u043a\u043e \u0445\u0430\u0440\u0430\u043a\u0442\u0435\u0440\u0438\u0441\u0442\u0438\u0447\u043d\u0438 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u0430 \u043d\u0430 \u0440\u0430\u0432\u043d\u043e\u0441\u0442\u0440\u0430\u043d\u043d\u0438\u044f \u0442\u0440\u0438\u044a\u0433\u044a\u043b\u043d\u0438\u043a, \u0431\u0440\u043e\u0439 3, 1992 \u0433., \u0441\u0442\u0440. 8<br \/>2001<br \/>\u041d\u0435\u0440\u0430\u0432\u0435\u043d\u0441\u0442\u0432\u043e \u043d\u0430 &#8230; 180 \u0433\u043e\u0434\u0438\u043d\u0438, \u0431\u0440\u043e\u0439 5, 2001 \u0433., \u0441\u044a\u0430\u0432\u0442. \u0418\u0432. \u0421\u043b\u0430\u0432\u043e\u0432<br \/>2002<br \/>\u0413\u0435\u043e\u043c\u0435\u0442\u0440\u0438\u044f \u0432 \u0442\u0440\u0438\u0433\u043e\u043d\u043e\u043c\u0435\u0442\u0440\u0438\u0447\u043d\u0438 \u043f\u0440\u0435\u0441\u043c\u044f\u0442\u0430\u043d\u0438\u044f, \u0431\u0440\u043e\u0439 2, 2002 \u0433., \u0441\u044a\u0430\u0432\u0442. \u0418\u0432\u0430\u043d \u0421\u043b\u0430\u0432\u043e\u0432;<br \/>\u0414\u0435\u043b\u0435\u043d\u0438\u0435 \u043d\u0430 \u0434\u0440\u043e\u0431\u0438 \u2013 \u043a\u043e\u043d\u0442\u0440\u043e\u043b \u0438 \u0441\u0430\u043c\u043e\u043a\u043e\u043d\u0442\u0440\u043e\u043b, \u0431\u0440\u043e\u0439 1, 2002 \u0433.<br \/>\u041f\u0440\u043e\u0446\u0435\u043d\u0442\u0438, \u041c\u043d\u043e\u0433\u043e\u0441\u0442\u0435\u043d\u0438 \u2013 \u043a\u043e\u043d\u0442\u0440\u043e\u043b \u0438 \u0441\u0430\u043c\u043e\u043a\u043e\u043d\u0442\u0440\u043e\u043b, \u0431\u0440\u043e\u0439 2, 2002 \u0433.<br \/>\u0423\u043c\u043d\u043e\u0436\u0435\u043d\u0438\u0435 \u0441 \u043c\u043d\u043e\u0433\u043e\u0446\u0438\u0444\u0440\u0435\u043d\u043e \u0447\u0438\u0441\u043b\u043e, \u041a\u043e\u043d\u0442\u0440\u043e\u043b \u0438 \u0441\u0430\u043c\u043e\u043a\u043e\u043d\u0442\u0440\u043e\u043b, \u0431\u0440\u043e\u0439 4, 2002 \u0433.<br \/>2004<br \/>\u0417\u0430 \u0434\u0435\u043b\u0435\u043d\u0438\u0435\u0442\u043e \u043d\u0430 \u0447\u0438\u0441\u043b\u0430, \u0437\u0430\u0432\u044a\u0440\u0448\u0432\u0430\u0449\u0438 \u043d\u0430 9, \u0431\u0440\u043e\u0439 1, 2004 \u0433.;<br \/>\u041d\u044f\u043a\u043e\u043b\u043a\u043e \u0437\u0430\u0434\u0430\u0447\u0438 \u0437\u0430 &#8230; \u0445\u0430\u0440\u043c\u043e\u043d\u0438\u0447\u043d\u0438\u044f \u0440\u0435\u0434, \u0431\u0440\u043e\u0439 3, 2004 \u0433.<br \/>\u0426\u044f\u043b\u0430\u0442\u0430 \u0447\u0430\u0441\u0442 \u043d\u0430 \u0447\u0438\u0441\u043b\u043e\u0442\u043e, \u0431\u0440\u043e\u0439 5, 2004 \u0433.<br \/>2011<br \/>\u0420\u0430\u0437\u043c\u0438\u0448\u043b\u0435\u043d\u0438\u044f \u0432\u044a\u0440\u0445\u0443 \u0434\u0432\u0435 \u0437\u0430\u0434\u0430\u0447\u0438, \u0431\u0440\u043e\u0439 3, 2011 \u0433.<br \/>2012<br \/>\u0415\u0434\u043d\u0430 \u0437\u0430\u0434\u0430\u0447\u0430 \u0437\u0430 \u043f\u0440\u0435\u0441\u043c\u044f\u0442\u0430\u043d\u0435 \u043d\u0430 \u0441\u0431\u043e\u0440 &#8230; \u0438 \u043e\u0449\u0435 \u043d\u044f\u043a\u043e\u043b\u043a\u043e \u0442\u0430\u043a\u0438\u0432\u0430, \u0431\u0440\u043e\u0439 6, 2012 \u0433.<br \/><br \/><strong>\u041c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u043a\u0430 \u0438 \u043c\u0430\u0442\u0435\u043c\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u043e \u043e\u0431\u0440\u0430\u0437\u043e\u0432\u0430\u043d\u0438\u0435 (Bulgaria) <\/strong><br \/>\u0438\u0437\u0434\u0430\u043d\u0438\u0435 \u043d\u0430 \u0411\u044a\u043b\u0433\u0430\u0440\u0441\u043a\u0430\u0442\u0430 \u0430\u043a\u0430\u0434\u0435\u043c\u0438\u044f \u043d\u0430 \u043d\u0430\u0443\u043a\u0438\u0442\u0435<br \/>1987<br \/>\u041d\u044f\u043a\u043e\u0438 \u043d\u0435\u043e\u0431\u0445\u043e\u0434\u0438\u043c\u0438 \u0438 \u0434\u043e\u0441\u0442\u0430\u0442\u044a\u0447\u043d\u0438 \u0443\u0441\u043b\u043e\u0432\u0438\u044f \u0437\u0430 \u043f\u043e\u043f\u0443\u043f\u0440\u0430\u0432\u0438\u043b\u0435\u043d \u0442\u0435\u0442\u0440\u0430\u0435\u0434\u044a\u0440, \u0421\u043e\u0444\u0438\u044f, \u0411\u0410\u041d, 1987 \u0433.<br \/>1988<br \/>\u0422\u043e\u0447\u043a\u0430\u0442\u0430 \u043d\u0430 \u041c\u043e\u043d\u0436 \u0437\u0430 \u043f\u043e\u043b\u0443\u043f\u0440\u0430\u0432\u0438\u043b\u043d\u0438 \u0438 \u043f\u0440\u0430\u0432\u0438\u043b\u043d\u0438 \u0442\u0435\u0442\u0440\u0430\u0435\u0434\u0440\u0438, \u0421\u043e\u0444\u0438\u044f, \u0411\u0410\u041d, 1988 \u0433., \u0441. 562-565<br \/>1989<br \/>\u041d\u044f\u043a\u043e\u0439 \u043d\u0435\u0440\u0430\u0432\u0435\u043d\u0441\u0442\u0432\u0430 \u0432 \u043e\u0440\u0442\u043e\u0446\u0435\u043d\u0442\u0440\u0438\u0447\u043d\u0438\u044f \u0442\u0435\u0442\u0440\u0430\u0435\u0434\u044a\u0440, \u0421., \u0411\u0410\u041d, 1989 \u0433., \u0441. 678-681<br \/>1990<br \/>\u041a\u043e\u043d\u043a\u0443\u0440\u0441\u043d\u0438\u0442\u0435 \u0437\u0430\u0434\u0430\u0447\u0438 \u0438 \u0435\u0434\u0438\u043d \u043f\u043e\u0434\u0445\u043e\u0434 \u0437\u0430 \u043f\u043e\u0432\u0438\u0448\u0430\u0432\u0430\u043d\u0435 \u043d\u0430 \u0442\u0432\u043e\u0440\u0447\u0435\u0441\u043a\u0430\u0442\u0430 \u0430\u043a\u0442\u0438\u0432\u043d\u043e\u0441\u0442 \u043d\u0430 \u0443\u0447\u0435\u043d\u0438\u0446\u0438\u0442\u0435, \u0421\u043e\u0444\u0438\u044f, \u0411\u0410\u041d , 1990 \u0433., \u0441. 499-503<\/p><\/div><\/div><\/div>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Lyubomir Lyubenov Mathematics teacher. Born on 6th March 1960. Graduated from Plovdiv University in 1981.Worked as a mathematics teacher in secondary and higher education, and also in the state administration of Bulgaria from 2002 until 2012.Founder of the international mathematics tournament &#8222;Drouzhba&#8220; (\u201e Mathematics Competitions \u201d &#8211; &#8222;Drouzhba&#8220; Mathematical&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"footnotes":""},"class_list":["post-118","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/pages\/118"}],"collection":[{"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/comments?post=118"}],"version-history":[{"count":5,"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/pages\/118\/revisions"}],"predecessor-version":[{"id":241,"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/pages\/118\/revisions\/241"}],"wp:attachment":[{"href":"https:\/\/mathwithoutborders.bg\/public_html\/en\/index.php\/wp-json\/wp\/v2\/media?parent=118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}