// Numbas version: exam_results_page_options {"name": "Factorise the quadratic expression", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"rulesets": {}, "extensions": [], "variablesTest": {"condition": "a <> b\na <> 0\nb <> 0", "maxRuns": 100}, "name": "Factorise the quadratic expression", "ungrouped_variables": ["a", "b"], "metadata": {"description": "

Testing factorisation of quadratics.

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The first step is to find two numbers that add together to give $\\var{a+b}$ and multiply to give $\\var{a*b}$.

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These are $\\var{a}$ and $\\var{b}$.

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We split the $x$-term using $\\simplify{{a + b}x = {a} x + {b} x}$ and work as follows:

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\\[\\begin{aligned}\\simplify{x^2 + {a + b} x + {a*b}} &= \\simplify{x^2 + {a} x + {b} x + {a*b}} \\\\ &= \\simplify{x(x + {a}) + {b}(x + {a})} \\\\ &= \\simplify{(x + {b})(x + {a})}\\end{aligned}\\]

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Factorise the following quadratic.

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$\\simplify{x^2 + {a + b}x + {a*b}}$

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One of the factors.

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The second factor.

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