{"id":21196,"date":"2026-05-25T22:26:58","date_gmt":"2026-05-25T16:26:58","guid":{"rendered":"https:\/\/mcqacademy.com\/en\/mcq\/use-an-algebraic-identity-to-expand-2\/"},"modified":"2026-05-25T22:26:58","modified_gmt":"2026-05-25T16:26:58","slug":"use-an-algebraic-identity-to-expand-2","status":"publish","type":"mcq","link":"https:\/\/mcqacademy.com\/en\/mcq\/use-an-algebraic-identity-to-expand-2\/","title":{"rendered":"Use an algebraic identity to expand"},"content":{"rendered":"<p>Expand and simplify: (x + 1)(x &#8211; 1).<\/p>\n<ul class=\"quiz-options\">\n<li>2x &#8211; 2<\/li>\n<li>x\u00b2 + 2x &#8211; 1<\/li>\n<li>x\u00b2 &#8211; 1<\/li>\n<li>x\u00b2 &#8211; 2x &#8211; 1<\/li>\n<li>x\u00b2 + 1<\/li>\n<\/ul>\n","protected":false},"author":39,"featured_media":0,"comment_status":"open","ping_status":"closed","template":"","topic":[2708,2738],"subject":[2750],"education_level":[1894],"class_list":["post-21196","mcq","type-mcq","status-publish","hentry","topic-algebraic-identities","topic-polynomials","subject-advanced-mathematics","education_level-grade-8"],"mcq_note":"This is the difference of two squares: (a + b)(a \u2212 b) = a\u00b2 \u2212 b\u00b2. So the answer is x\u00b2 \u2212 1. This identity is useful because the middle terms cancel. After expansion, only the square of the first term minus the square of the second term remains. Expanding the chosen answer is a good check that it returns the original expression. The correct answer is x\u00b2 - 1, which matches the calculation or reasoning shown.","mcq_options":[{"right":"no","answer":"2x - 2"},{"right":"no","answer":"x\u00b2 + 2x - 1"},{"right":"yes","answer":"x\u00b2 - 1"},{"right":"no","answer":"x\u00b2 - 2x - 1"},{"right":"no","answer":"x\u00b2 + 1"}],"multi_answers":"no","subject_terms":[{"id":2750,"title":"Advanced Mathematics","slug":"advanced-mathematics"}],"topic_terms":[{"id":2708,"title":"Algebraic Identities","slug":"algebraic-identities"},{"id":2738,"title":"Polynomials","slug":"polynomials"}],"_links":{"self":[{"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/mcq\/21196","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/mcq"}],"about":[{"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/types\/mcq"}],"author":[{"embeddable":true,"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/users\/39"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/comments?post=21196"}],"wp:attachment":[{"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/media?parent=21196"}],"wp:term":[{"taxonomy":"topic","embeddable":true,"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/topic?post=21196"},{"taxonomy":"subject","embeddable":true,"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/subject?post=21196"},{"taxonomy":"education_level","embeddable":true,"href":"https:\/\/mcqacademy.com\/en\/wp-json\/wp\/v2\/education_level?post=21196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}