{"id":"cb_question_bank:307d3be2-c903-4943-8e6c-d5cb417992cd","source_id":"cb_question_bank","source_item_id":"307d3be2-c903-4943-8e6c-d5cb417992cd","external_id":"16d897b1-c597-4b7a-b4ee-ecba3515085e","ibn":null,"question_id":"433184f1","program":"SAT","module":"math","domain_code":"P","domain":"Advanced Math","skill_code":"P.A.","skill":"Equivalent expressions","difficulty":"H","score_band":6,"answer_type":"mcq","answer_source":"key","layout_warning":null,"form_id":null,"module_number":null,"position":null,"stem":"Which expression is equivalent to StartFraction 4 Over 4 x minus 5 EndFraction minus StartFraction 1 Over x plus 1 EndFraction ?","stimulus":"","stimulus_html":null,"stem_html":"<p>Which expression is equivalent to <math alttext=\"StartFraction 4 Over 4 x minus 5 EndFraction minus StartFraction 1 Over x plus 1 EndFraction\"><mrow>\n\t<mrow>\n\t\t<mfrac>\n\t\t\t<mn>4</mn>\n\t\t\t<mrow>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mn>4</mn>\n\t\t\t\t\t<mi>x</mi>\n\t\t\t\t</mrow>\n\t\t\t\t<mo>-</mo>\n\t\t\t\t<mn>5</mn>\n\t\t\t</mrow>\n\t\t</mfrac>\n\t</mrow>\n\t<mo>-</mo>\n\t<mfrac>\n\t\t<mn>1</mn>\n\t\t<mrow>\n\t\t\t<mi>x</mi>\n\t\t\t<mo>+</mo>\n\t\t\t<mn>1</mn>\n\t\t</mrow>\n\t</mfrac>\n</mrow>\n</math>?</p>","rationale_html":"<p>Choice D is correct. The expression&nbsp;<math alttext=\"StartFraction 4 Over 4 x minus 5 EndFraction minus StartFraction 1 Over x plus 1 EndFraction\"><mfrac><mn>4</mn><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfrac><mo>-</mo><mfrac><mn>1</mn><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfrac></math> can be rewritten as&nbsp;<math alttext=\"StartFraction 4 Over 4 x minus 5 EndFraction plus StartFraction left parenthesis negative 1 right parenthesis Over x plus 1 EndFraction\"><mfrac><mn>4</mn><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfrac><mo>+</mo><mfrac><mfenced><mrow><mo>-</mo><mn>1</mn></mrow></mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfrac></math>. To add the two terms of this expression, the terms can be rewritten with a common denominator. Since <math alttext=\"StartFraction x plus 1 Over x plus 1 EndFraction equals 1\"><mfrac><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfrac><mo>=</mo><mn>1</mn></math>, the expression <math alttext=\"StartFraction 4 Over 4 x minus 5 EndFraction\"><mfrac><mn>4</mn><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfrac></math> can be rewritten as <math alttext=\"StartFraction left parenthesis x plus 1 right parenthesis left parenthesis 4 right parenthesis Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mn>4</mn></mfenced></mrow><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac></math>. Since <math alttext=\"StartFraction 4 x minus 5 Over 4 x minus 5 EndFraction equals 1\"><mfrac><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfrac><mo>=</mo><mn>1</mn></math>, the expression <math alttext=\"StartFraction negative 1 Over x plus 1 EndFraction\"><mfrac><mrow><mo>-</mo><mn>1</mn></mrow><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfrac></math> can be rewritten as <math alttext=\"StartFraction left parenthesis 4 x minus 5 right parenthesis left parenthesis negative 1 right parenthesis Over left parenthesis 4 x minus 5 right parenthesis left parenthesis x plus 1 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced><mfenced><mrow><mo>-</mo><mn>1</mn></mrow></mfenced></mrow><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced></mrow></mfrac></math>. Therefore, the expression&nbsp;<math alttext=\"StartFraction 4 Over 4 x minus 5 EndFraction plus StartFraction left parenthesis negative 1 right parenthesis Over x plus 1 EndFraction\"><mfrac><mn>4</mn><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfrac><mo>+</mo><mfrac><mfenced><mrow><mo>-</mo><mn>1</mn></mrow></mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfrac></math> can be rewritten as&nbsp;<math alttext=\"StartFraction left parenthesis x plus 1 right parenthesis left parenthesis 4 right parenthesis Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction plus StartFraction left parenthesis 4 x minus 5 right parenthesis left parenthesis negative 1 right parenthesis Over left parenthesis 4 x minus 5 right parenthesis left parenthesis x plus 1 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mn>4</mn></mfenced></mrow><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac><mo>+</mo><mfrac><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced><mfenced><mrow><mo>-</mo><mn>1</mn></mrow></mfenced></mrow><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced></mrow></mfrac></math>, which is equivalent to <math alttext=\"StartFraction left parenthesis x plus 1 right parenthesis left parenthesis 4 right parenthesis plus left parenthesis 4 x minus 5 right parenthesis left parenthesis negative 1 right parenthesis Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mn>4</mn></mfenced><mo>+</mo><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced><mfenced><mrow><mo>-</mo><mn>1</mn></mrow></mfenced></mrow><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac></math>.&nbsp;Applying the distributive property to each term of the numerator yields <math alttext=\"StartFraction left parenthesis 4 x plus 4 right parenthesis plus left parenthesis minus 4 x plus 5 right parenthesis Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>+</mo><mn>4</mn></mrow></mfenced><mo>+</mo><mfenced><mrow><mo>-</mo><mn>4</mn><mi>x</mi><mo>+</mo><mn>5</mn></mrow></mfenced></mrow><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac></math>, or&nbsp; <math alttext=\"StartFraction left parenthesis 4 x plus left parenthesis minus 4 x right parenthesis right parenthesis plus left parenthesis 4 plus 5 right parenthesis Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mfrac><mrow><mfenced><mrow><mn>4</mn><mi>x</mi><mo>+</mo><mfenced><mrow><mo>-</mo><mn>4</mn><mi>x</mi></mrow></mfenced></mrow></mfenced><mo>+</mo><mfenced><mrow><mn>4</mn><mo>+</mo><mn>5</mn></mrow></mfenced></mrow><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac></math>. Adding like terms in the numerator yields&nbsp;<math alttext=\"StartFraction 9 Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mfrac><mn>9</mn><mrow><mfenced><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow></mfenced><mfenced><mrow><mn>4</mn><mi>x</mi><mo>-</mo><mn>5</mn></mrow></mfenced></mrow></mfrac></math>.</p>\n<p>Choice A is incorrect and may result from conceptual or calculation errors.</p>\n<p>Choice B is incorrect and may result from conceptual or calculation errors.</p>\n<p>Choice C is incorrect and may result from conceptual or calculation errors.</p>","correct_answer":["D"],"has_media":false,"has_mathml":true,"has_table":false,"source_created_at":"2023-08-02T20:25:59.821000+00:00","source_updated_at":"2023-08-02T20:25:59.821000+00:00","options":[{"label":"A","content_html":"<p><math alttext=\"StartFraction 1 Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mrow>\n\t<mfrac>\n\t\t<mn>1</mn>\n\t\t<mrow>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t<mo>+</mo>\n\t\t\t\t\t<mn>1</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mrow>\n\t\t\t\t\t\t<mn>4</mn>\n\t\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t</mrow>\n\t\t\t\t\t<mo>-</mo>\n\t\t\t\t\t<mn>5</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t</mrow>\n\t</mfrac>\n</mrow>\n</math></p>","ord":0},{"label":"B","content_html":"<p><math alttext=\"StartFraction 3 Over 3 x minus 6 EndFraction\"><mrow>\n\t<mfrac>\n\t\t<mn>3</mn>\n\t\t<mrow>\n\t\t\t<mrow>\n\t\t\t\t<mn>3</mn>\n\t\t\t\t<mi>x</mi>\n\t\t\t</mrow>\n\t\t\t<mo>-</mo>\n\t\t\t<mn>6</mn>\n\t\t</mrow>\n\t</mfrac>\n</mrow>\n</math></p>","ord":1},{"label":"C","content_html":"<p><math alttext=\"minus StartFraction 1 Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mrow>\n\t<mo>-</mo>\n\t<mfrac>\n\t\t<mn>1</mn>\n\t\t<mrow>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t<mo>+</mo>\n\t\t\t\t\t<mn>1</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mrow>\n\t\t\t\t\t\t<mn>4</mn>\n\t\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t</mrow>\n\t\t\t\t\t<mo>-</mo>\n\t\t\t\t\t<mn>5</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t</mrow>\n\t</mfrac>\n</mrow>\n</math></p>","ord":2},{"label":"D","content_html":"<p><math alttext=\"StartFraction 9 Over left parenthesis x plus 1 right parenthesis left parenthesis 4 x minus 5 right parenthesis EndFraction\"><mrow>\n\t<mfrac>\n\t\t<mn>9</mn>\n\t\t<mrow>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t<mo>+</mo>\n\t\t\t\t\t<mn>1</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t\t<mfenced>\n\t\t\t\t<mrow>\n\t\t\t\t\t<mrow>\n\t\t\t\t\t\t<mn>4</mn>\n\t\t\t\t\t\t<mi>x</mi>\n\t\t\t\t\t</mrow>\n\t\t\t\t\t<mo>-</mo>\n\t\t\t\t\t<mn>5</mn>\n\t\t\t\t</mrow>\n\t\t\t</mfenced>\n\t\t</mrow>\n\t</mfrac>\n</mrow>\n</math></p>","ord":3}],"attribution":{"source_id":"cb_question_bank","source_name":"College Board digital SAT question bank (community dump)","rights_holder":"College Board","canonical_url":"https://satsuitequestionbank.collegeboard.org/","retrieved_from":"https://raw.githubusercontent.com/mdn522/sat-question-bank/main/data/cb-digital-questions.json","attribution":"SAT practice questions © College Board, from the official SAT Suite Question Bank. Retrieved via the community dump at github.com/mdn522/sat-question-bank.","disclaimer":"SAT® and PSAT/NMSQT® are trademarks registered by the College Board, which is not affiliated with, does not sponsor, and does not endorse this project.","license":"College Board copyright; source repository carries no licence. Local use only.","redistributable":false,"item_count":2017}}