// Numbas version: exam_results_page_options {"name": "Anna's Expansion of two brackets: Linear 2 positive coefficients - test", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"parts": [{"variableReplacementStrategy": "originalfirst", "stepsPenalty": "0", "customMarkingAlgorithm": "", "marks": 0, "type": "gapfill", "sortAnswers": false, "useCustomName": false, "gaps": [{"showPreview": true, "customMarkingAlgorithm": "", "maxlength": {"partialCredit": 0, "message": "

Input your answer as a quadratic in $x$, in the form $ax^2+bx+c$ for appropriate integers $a,\\;b,\\;c$.

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Do not include brackets in your answer. Input your answer as a quadratic in $x$, in the form $ax^2+bx+c$ for appropriate integers $a,\\;b,\\;c$.

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Input your answer as a quadratic in $x$, in the form $ax^2+bx+c$ for appropriate integers $a,\\;b,\\;c$.

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There are many ways to expand an expression such as $(ax+b)(cx+d)$.

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One method is sometimes referred to as FOIL, a mnemonic to help us remember which terms to multiply with one another:

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First    $ax \\times cx$

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Outside    $ax \\times d$

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Inside    $b \\times cx$

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Last    $b \\times d$

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We then add these together and simplify by collecting like terms.

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$\\simplify[std]{({a}x+{b})({c}x+{d})}=\\;$[[0]].

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Your answer should be a quadratic in $x$ and should not include any brackets.

\n

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There are many ways to expand an expression such as $(ax+b)(cx+d)$.

\n

One method is sometimes referred to as FOIL, a mnemonic to help us remember which terms to multiply with one another:

\n

First    $ax \\times cx$

\n

Outside    $ax \\times d$

\n

Inside    $b \\times cx$

\n

Last    $b \\times d$

\n

We then add these together and simplify by collecting like terms.

\n

\n

\n

\\[\\begin{eqnarray*}\\simplify[std]{ ({a}x+{b})({c}x+{d})}&=&(\\var{a}x\\times\\var{c}x)+(\\var{a}x\\times\\var{d})+(\\var{b}\\times\\var{c}x)+(\\var{b}\\times\\var{d})\\\\&=&(\\var{a*c}x^2)+(\\var{a*d}x)+(\\var{b*c}x)+(\\var{b*d})\\\\&=&\\simplify[std]{{a*c}x^2+{(a*d+b*c)}x+{b*d}}\\end{eqnarray*}\\]

\n

 

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Expand the following to give a quadratic in $x$.

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Expand $(ax+b)(cx+d)$.

\n

rebelmaths

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