// Numbas version: exam_results_page_options {"name": "Solving quadratic equations 1(c)", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"rulesets": {}, "functions": {}, "type": "question", "preamble": {"css": "", "js": ""}, "statement": "
The following equation can be converted into a quadratic equation:
\n\\(\\var{a1}x+\\frac{\\simplify{{a1}*{b1}*{c1}}}{x}=\\simplify{{a1}*({b1}+{c1})}\\)
", "showQuestionGroupNames": false, "name": "Solving quadratic equations 1(c)", "tags": [], "variable_groups": [], "variablesTest": {"maxRuns": "1", "condition": ""}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "Solving quadratic equations using a formula
"}, "advice": "\\(\\var{a1}x+\\frac{\\simplify{{a1}*{b1}*{c1}}}{x}=\\simplify{{a1}*({b1}+{c1})}\\)
\nWe clear the fraction in the equation by multiplying across by \\(x\\)
\n\\(\\var{a1}x^2+\\simplify{{a1}*{b1}*{c1}}=\\simplify{{a1}*({b1}+{c1})}x\\)
\nBringing all the terms to the left hand side and putting them in order of their powers of \\(x\\) gives
\n\\(\\var{a1}x^2-\\simplify{{a1}*({b1}+{c1})}x+\\simplify{{a1}*{b1}*{c1}}=0\\)
\nThe formula for solving a quadratic equation of the form \\(ax^2+bx+c=0\\) is given by
\n\\(x=\\frac{-b\\pm \\sqrt{b^2-4ac}}{2a}\\)
\nIn this example \\(a=\\var{a1},\\,\\,\\,b=\\simplify{+-{a1}*({b1}+{c1})}\\) and \\(c=\\simplify{{a1}*{b1}*{c1}}\\)
\n\\(x=\\frac{\\var{b}\\pm \\sqrt{(-\\var{b})^2-4*\\var{a1}*\\var{c}}}{2*\\var{a1}}\\)
\n\\(x=\\frac{\\var{b}\\pm \\sqrt{\\simplify{{b}^2-4*{a1}*{c}}}}{\\simplify{2*{a1}}}\\)
\n\\(x=\\simplify{{b}+({b}^2-4*{a1}*{c})^0.5}/\\simplify{2*{a1}}=\\simplify{({b}+({b}^2-4*{a1}*{c})^0.5)/(2*{a1})}\\) or \\(x=\\simplify{{b}-({b}^2-4*{a1}*{c})^0.5}/\\simplify{2*{a1}}=\\simplify{({b}-({b}^2-4*{a1}*{c})^0.5)/(2*{a1})}\\)
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\n\\(x = \\) [[0]]
\nType in the lesser of the two values that satisfies the equation.
\n\\(x = \\) [[1]]
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