// Numbas version: finer_feedback_settings {"name": "Solve a logarithmic equation", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"extensions": [], "parts": [{"scripts": {}, "marks": 0, "variableReplacements": [], "type": "gapfill", "showCorrectAnswer": true, "prompt": "
Calculate the value of \\(x\\) that satisfies the equation when \\(y=\\var{d}\\).
\nInput your answer correct to three decimal places.
\n\\(x = \\) [[0]]
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\n\\(y=\\var{a}log(\\var{b}x+\\var{c}))\\)
\n", "rulesets": {}, "variable_groups": [], "ungrouped_variables": ["a", "b", "c", "d"], "name": "Solve a logarithmic equation", "functions": {}, "tags": [], "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "Solve a logarithmic equation
"}, "variablesTest": {"condition": "", "maxRuns": 100}, "advice": "\\(\\var{a}log(\\var{b}x+\\var{c})=\\var{d}\\)
\nDivide across by \\(\\var{a}\\)
\n\\(log(\\var{b}x+\\var{c})=\\var{d}/\\var{a}=\\simplify{{d}/{a}}\\)
\n\\(\\var{b}x+\\var{c}=10^{\\simplify{{d}/{a}}}\\)
\n\\(\\var{b}x+\\var{c}=\\simplify{10^{{d}/{a}}}\\)
\n\\(\\var{b}x=\\simplify{10^{{d}/{a}}}-\\var{c}\\)
\n\\(\\var{b}x=\\simplify{10^{{d}/{a}}-{c}}\\)
\n\\(x=\\simplify{(10^{{d}/{a}}-{c})/{b}}\\)
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