{"id":233738,"date":"2025-06-13T11:08:34","date_gmt":"2025-06-13T11:08:34","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=233738"},"modified":"2025-06-13T11:08:37","modified_gmt":"2025-06-13T11:08:37","slug":"using-the-factor-theorem-show-that-2x-1-is-a-factor-of-2x3-3x2-11x-6","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/13\/using-the-factor-theorem-show-that-2x-1-is-a-factor-of-2x3-3x2-11x-6\/","title":{"rendered":"Using the factor theorem, show that 2x + 1 is a factor of 2x^3 + 3x^2 &#8211; 11x &#8211; 6."},"content":{"rendered":"\n<p>Using the factor theorem, show that 2x + 1 is a factor of 2x^3 + 3x^2 &#8211; 11x &#8211; 6.<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-0-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To show that 2x+12x + 12x+1 is a factor of 2&#215;3+3&#215;2\u221211x\u221262x^3 + 3x^2 &#8211; 11x &#8211; 62&#215;3+3&#215;2\u221211x\u22126 using the <strong>Factor Theorem<\/strong>, follow these steps:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1: Use the Factor Theorem<\/strong><\/h3>\n\n\n\n<p>The Factor Theorem states:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>If f(a)=0f(a) = 0f(a)=0, then (x\u2212a)(x &#8211; a)(x\u2212a) is a factor of the polynomial f(x)f(x)f(x).<\/p>\n<\/blockquote>\n\n\n\n<p>Given the expression 2x+12x + 12x+1, rewrite it in the form x\u2212ax &#8211; ax\u2212a.<br>To do this, solve: 2x+1=0\u21d2x=\u2212122x + 1 = 0 \\Rightarrow x = -\\frac{1}{2}2x+1=0\u21d2x=\u221221\u200b<\/p>\n\n\n\n<p>Now evaluate the polynomial: f(x)=2&#215;3+3&#215;2\u221211x\u22126f(x) = 2x^3 + 3x^2 &#8211; 11x &#8211; 6f(x)=2&#215;3+3&#215;2\u221211x\u22126<\/p>\n\n\n\n<p>at x=\u221212x = -\\frac{1}{2}x=\u221221\u200b.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Substitute x=\u221212x = -\\frac{1}{2}x=\u221221\u200b into the polynomial<\/strong><\/h3>\n\n\n\n<p>f(\u221212)=2(\u221212)3+3(\u221212)2\u221211(\u221212)\u22126f\\left(-\\frac{1}{2}\\right) = 2\\left(-\\frac{1}{2}\\right)^3 + 3\\left(-\\frac{1}{2}\\right)^2 &#8211; 11\\left(-\\frac{1}{2}\\right) &#8211; 6f(\u221221\u200b)=2(\u221221\u200b)3+3(\u221221\u200b)2\u221211(\u221221\u200b)\u22126<\/p>\n\n\n\n<p>Now calculate each term:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>(\u221212)3=\u221218\\left(-\\frac{1}{2}\\right)^3 = -\\frac{1}{8}(\u221221\u200b)3=\u221281\u200b<\/li>\n\n\n\n<li>(\u221212)2=14\\left(-\\frac{1}{2}\\right)^2 = \\frac{1}{4}(\u221221\u200b)2=41\u200b<\/li>\n<\/ul>\n\n\n\n<p>f(\u221212)=2(\u221218)+3(14)+112\u22126f\\left(-\\frac{1}{2}\\right) = 2\\left(-\\frac{1}{8}\\right) + 3\\left(\\frac{1}{4}\\right) + \\frac{11}{2} &#8211; 6f(\u221221\u200b)=2(\u221281\u200b)+3(41\u200b)+211\u200b\u22126 =\u221228+34+112\u22126=\u221214+34+112\u22126= -\\frac{2}{8} + \\frac{3}{4} + \\frac{11}{2} &#8211; 6 = -\\frac{1}{4} + \\frac{3}{4} + \\frac{11}{2} &#8211; 6=\u221282\u200b+43\u200b+211\u200b\u22126=\u221241\u200b+43\u200b+211\u200b\u22126<\/p>\n\n\n\n<p>Combine the terms:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u221214+34=24=12-\\frac{1}{4} + \\frac{3}{4} = \\frac{2}{4} = \\frac{1}{2}\u221241\u200b+43\u200b=42\u200b=21\u200b<\/li>\n\n\n\n<li>12+112=6\\frac{1}{2} + \\frac{11}{2} = 621\u200b+211\u200b=6<\/li>\n\n\n\n<li>6\u22126=06 &#8211; 6 = 06\u22126=0<\/li>\n<\/ul>\n\n\n\n<p>f(\u221212)=0f\\left(-\\frac{1}{2}\\right) = 0f(\u221221\u200b)=0<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 3: Conclusion<\/strong><\/h3>\n\n\n\n<p>Since f(\u221212)=0f\\left(-\\frac{1}{2}\\right) = 0f(\u221221\u200b)=0, by the <strong>Factor Theorem<\/strong>, x+12x + \\frac{1}{2}x+21\u200b is a factor of f(x)f(x)f(x).<br>Multiplying both sides of x+12x + \\frac{1}{2}x+21\u200b by 2 gives 2x+12x + 12x+1, so: 2x+1&nbsp;is&nbsp;a&nbsp;factor&nbsp;of&nbsp;2&#215;3+3&#215;2\u221211x\u22126\\boxed{2x + 1 \\text{ is a factor of } 2x^3 + 3x^2 &#8211; 11x &#8211; 6}2x+1&nbsp;is&nbsp;a&nbsp;factor&nbsp;of&nbsp;2&#215;3+3&#215;2\u221211x\u22126\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Summary Explanation (Like in textbooks)<\/strong><\/h3>\n\n\n\n<p>To determine whether 2x+12x + 12x+1 is a factor of the polynomial f(x)=2&#215;3+3&#215;2\u221211x\u22126f(x) = 2x^3 + 3x^2 &#8211; 11x &#8211; 6f(x)=2&#215;3+3&#215;2\u221211x\u22126, the <strong>Factor Theorem<\/strong> is applied. First, rewrite 2x+12x + 12x+1 in the form x\u2212ax &#8211; ax\u2212a by solving 2x+1=02x + 1 = 02x+1=0, which gives x=\u221212x = -\\frac{1}{2}x=\u221221\u200b. Then evaluate the polynomial at x=\u221212x = -\\frac{1}{2}x=\u221221\u200b. If the result is 0, then 2x+12x + 12x+1 is indeed a factor. Substituting x=\u221212x = -\\frac{1}{2}x=\u221221\u200b into the polynomial results in zero, confirming that the factor condition is satisfied. Thus, 2x+12x + 12x+1 is a factor of the polynomial.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-317.jpeg\" alt=\"\" class=\"wp-image-233739\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Using the factor theorem, show that 2x + 1 is a factor of 2x^3 + 3x^2 &#8211; 11x &#8211; 6. The Correct Answer and Explanation is: To show that 2x+12x + 12x+1 is a factor of 2&#215;3+3&#215;2\u221211x\u221262x^3 + 3x^2 &#8211; 11x &#8211; 62&#215;3+3&#215;2\u221211x\u22126 using the Factor Theorem, follow these steps: Step 1: Use the Factor [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-233738","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/233738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=233738"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/233738\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=233738"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=233738"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=233738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}