// Numbas version: exam_results_page_options {"name": "Expanding binomial products", "metadata": {"description": "", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "duration": 0, "percentPass": 0, "showQuestionGroupNames": false, "shuffleQuestionGroups": false, "showstudentname": true, "question_groups": [{"name": "Group", "pickingStrategy": "all-ordered", "pickQuestions": 1, "questionNames": ["", "", ""], "variable_overrides": [[], [], []], "questions": [{"name": "Expanding a binomial product (monic factors)", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}], "ungrouped_variables": ["a", "b"], "tags": ["binomial", "binomial product", "distributive law", "expanding", "Factorisation", "factorisation", "Factors", "factors", "monic", "quadratic"], "statement": "

Expand and simplify the following.

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$\\simplify{(x+{a[0]})(x+{b[0]})}$ = [[0]]

\n

\n

", "gaps": [{"notallowed": {"strings": ["(", ")"], "partialCredit": 0, "message": "

Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(x+{a[0]})(x+{b[0]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[0]})(x+{b[0]})}$$=$\n

$\\simplify{x(x+{b[0]})+{a[0]}(x+{b[0]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{x^2+{b[0]}x+{a[0]}x+{a[0]*b[0]}}$          (use the distributive law on each bracket)
$=$$\\simplify{x^2+{b[0]+a[0]}x+{a[0]*b[0]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[0]})(x+{b[0]})}$$=$\n

$\\simplify[basic]{x^2+{b[0]}x+{a[0]}x+{a[0]*b[0]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{x^2+{b[0]+a[0]}x+{a[0]*b[0]}}$          (collect like terms)
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$\\simplify{(x+{a[1]})(x+{b[1]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(x+{a[1]})(x+{b[1]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[1]})(x+{b[1]})}$$=$\n

$\\simplify{x(x+{b[1]})+{a[1]}(x+{b[1]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{x^2+{b[1]}x+{a[1]}x+{a[1]*b[1]}}$          (use the distributive law on each bracket)
$=$$\\simplify{x^2+{b[1]+a[1]}x+{a[1]*b[1]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[1]})(x+{b[1]})}$$=$\n

$\\simplify[basic]{x^2+{b[1]}x+{a[1]}x+{a[1]*b[1]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{x^2+{b[1]+a[1]}x+{a[1]*b[1]}}$          (collect like terms)
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$\\simplify{(m+{a[2]})(m+{b[2]})}$ = [[0]]

\n

\n

", "gaps": [{"notallowed": {"strings": ["(", ")"], "partialCredit": 0, "message": "

Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(m+{a[2]})(m+{b[2]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(m+{a[2]})(m+{b[2]})}$$=$\n

$\\simplify{m(m+{b[2]})+{a[2]}(m+{b[2]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{m^2+{b[2]}m+{a[2]}m+{a[2]*b[2]}}$          (use the distributive law on each bracket)
$=$$\\simplify{m^2+{b[2]+a[2]}m+{a[2]*b[2]}}$           (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(m+{a[2]})(m+{b[2]})}$$=$\n

$\\simplify[basic]{m^2+{b[2]}m+{a[2]}m+{a[2]*b[2]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{m^2+{b[2]+a[2]}m+{a[2]*b[2]}}$          (collect like terms)
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$\\simplify{(t+{a[3]})(t+{b[3]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(t+{a[3]})(t+{b[3]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(t+{a[3]})(t+{b[3]})}$$=$\n

$\\simplify{t(t+{b[3]})+{a[3]}(t+{b[3]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{t^2+{b[3]}t+{a[3]}t+{a[3]*b[3]}}$          (use the distributive law on each bracket)
$=$$\\simplify{t^2+{b[3]+a[3]}t+{a[3]*b[3]}}$\n

\n

          (collect like terms)

\n
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(t+{a[3]})(t+{b[3]})}$$=$\n

$\\simplify[basic]{t^2+{b[3]}t+{a[3]}t+{a[3]*b[3]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{t^2+{b[3]+a[3]}t+{a[3]*b[3]}}$          (collect like terms)
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$\\simplify{(x+{a[0]})(x-{a[0]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(x+{a[0]})(x-{a[0]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[0]})(x-{a[0]})}$$=$\n

$\\simplify{x(x-{a[0]})+{a[0]}(x-{a[0]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{x^2-{a[0]}x+{a[0]}x-{a[0]*a[0]}}$          (use the distributive law on each bracket)
$=$$\\simplify{x^2-{a[0]*a[0]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[0]})(x-{a[0]})}$$=$\n

$\\simplify[basic]{x^2-{a[0]}x+{a[0]}x-{a[0]*a[0]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{x^2-{a[0]*a[0]}}$          (collect like terms)
\n

Method 3 (difference of two squares)

\n

Notice that the product will expand to be a difference of two squares. Square the first term minus the square of the second term. 

\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[0]})(x-{a[0]})}$$=$\n

$\\simplify{x^2-{a[0]*a[0]}}$

\n
\n

          (difference of two squares)

\n
\n

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$\\simplify{(x+{a[2]})^2}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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It is important to realise that $\\simplify{(x+{a[2]})^2}=\\simplify{(x+{a[2]})(x+{a[2]})}$. Recall that squaring something is multiplying it by itself.

\n

 

\n

Method 1 (the distributive law)

\n

We expand $\\simplify{(x+{a[2]})(x+{a[2]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[2]})(x+{a[2]})}$$=$\n

$\\simplify{x(x+{a[2]})+{a[2]}(x+{a[2]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{x^2+{a[2]}x+{a[2]}x+{a[2]*a[2]}}$          (use the distributive law on each bracket)
$=$$\\simplify{x^2+{2*a[2]}x+{a[2]*a[2]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[2]})(x+{a[2]})}$$=$\n

$\\simplify[basic]{x^2+{a[2]}x+{a[2]}x+{a[2]*a[2]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{x^2+{2*a[2]}x+{a[2]*a[2]}}$          (collect like terms)
\n

Method 3 (perfect square)

\n

Notice that $\\simplify{(x+{a[2]})^2}$ is a perfect square. Square the first term, double the second term times the first, then square the last term, add them all together.

\n\n\n\n\n\n\n\n\n\n
$\\simplify{(x+{a[2]})}$$=$\n

$\\simplify{x^2+{2*a[2]}x+{a[2]*a[2]}}$

\n
\n

          (perfect square)

\n
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$\\simplify{(w+{a[1]})(w-{a[1]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(w+{a[1]})(w-{a[1]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(w+{a[1]})(w-{a[1]})}$$=$\n

$\\simplify{w(w-{a[1]})+{a[1]}(w-{a[1]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{w^2-{a[1]}w+{a[1]}w-{a[1]*a[1]}}$          (use the distributive law on each bracket)
$=$$\\simplify{w^2-{a[1]*a[1]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(w+{a[1]})(w-{a[1]})}$$=$\n

$\\simplify[basic]{w^2-{a[1]}w+{a[1]}w-{a[1]*a[1]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{w^2-{a[1]*a[1]}}$          (collect like terms)
\n

Method 3 (difference of two squares)

\n

Notice that the product will expand to be a difference of two squares. Square the first term minus the square of the second term. 

\n\n\n\n\n\n\n\n\n\n
$\\simplify{(w+{a[1]})(w-{a[1]})}$$=$\n

$\\simplify{w^2-{a[1]*a[1]}}$

\n
\n

          (difference of two squares)

\n
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$\\simplify{(r+{a[3]})(r+{a[3]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify{(r+{a[3]})(r+{a[3]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(r+{a[3]})(r+{a[3]})}$$=$\n

$\\simplify{r(r+{a[3]})+{a[3]}(r+{a[3]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify{r^2+{a[3]}r+{a[3]}r+{a[3]*a[3]}}$          (use the distributive law on each bracket)
$=$$\\simplify{r^2+{2*a[3]}r+{a[3]*a[3]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify{(r+{a[3]})(r+{a[3]})}$$=$\n

$\\simplify[basic]{r^2+{a[3]}r+{a[3]}r+{a[3]*a[3]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify{r^2+{2*a[3]}r+{a[3]*a[3]}}$          (collect like terms)
\n

Method 3 (perfect square)

\n

Notice that $\\simplify{(r+{a[3]})(r+{a[3]})}$ is a perfect square. Square the first term, double the second term times the first, then square the last term, add them all together.

\n\n\n\n\n\n\n\n\n\n
$\\simplify{(r+{a[3]})(r+{a[3]})}$$=$\n

$\\simplify{r^2+{2*a[3]}r+{a[3]*a[3]}}$

\n
\n

          (perfect square)

\n
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Expand and simplify the following.

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

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify[basic]{({c[0]}x+{a[0]})({d[0]}x+{b[0]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[basic]{({c[0]}x+{a[0]})({d[0]}x+{b[0]})}$$=$\n

$\\simplify[basic]{{c[0]}x({d[0]}x+{b[0]})+{a[0]}({d[0]}x+{b[0]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify[basic]{{c[0]*d[0]}x^2+{c[0]*b[0]}x+{d[0]*a[0]}x+{a[0]*b[0]}}$          (use the distributive law on each bracket)
$=$$\\simplify[basic]{{c[0]*d[0]}x^2+{d[0]*a[0]+c[0]*b[0]}x+{a[0]*b[0]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[basic]{({c[0]}x+{a[0]})({d[0]}x+{b[0]})}$$=$\n

$\\simplify[basic]{{c[0]*d[0]}x^2+{c[0]*b[0]}x+{d[0]*a[0]}x+{a[0]*b[0]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify[basic]{{c[0]*d[0]}x^2+{d[0]*a[0]+c[0]*b[0]}x+{a[0]*b[0]}}$          (collect like terms)
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$\\simplify[basic]{({c[1]}x+{a[1]})({d[1]}x+{b[1]})}$ = [[0]]

\n

\n

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Ensure you don't use brackets in your answer.

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Method 1 (the distributive law)

\n

We expand $\\simplify[basic]{({c[1]}x+{a[1]})({d[1]}x+{b[1]})}$ one bracket at a time. 

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[basic]{({c[1]}x+{a[1]})({d[1]}x+{b[1]})}$$=$\n

$\\simplify[basic]{{c[1]}x({d[1]}x+{b[1]})+{a[1]}({d[1]}x+{b[1]})}$

\n
\n

          (each term in one bracket times the entire other bracket)

\n
$=$$\\simplify[basic]{{c[1]*d[1]}x^2+{c[1]*b[1]}x+{d[1]*a[1]}x+{a[1]*b[1]}}$          (use the distributive law on each bracket)
$=$$\\simplify[basic]{{c[1]*d[1]}x^2+{d[1]*a[1]+c[1]*b[1]}x+{a[1]*b[1]}}$          (collect like terms)
\n

Method 2 (FOIL)

\n

Multiply the First terms in each bracket, then the Outer terms, then the Inner terms and then the Last terms. Add them all together.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\simplify[basic]{({c[1]}x+{a[1]})({d[1]}x+{b[1]})}$$=$\n

$\\simplify[basic]{{c[1]*d[1]}x^2+{c[1]*b[1]}x+{d[1]*a[1]}x+{a[1]*b[1]}}$

\n
\n

          (First, Outer, Inner, Last)

\n
$=$$\\simplify[basic]{{c[1]*d[1]}x^2+{d[1]*a[1]+c[1]*b[1]}x+{a[1]*b[1]}}$          (collect like terms)
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Expand and simplify the following.

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