// Numbas version: exam_results_page_options {"name": "Simultaneous Equations with integers as solutions.", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "ungrouped_variables": ["a", "b", "c", "d", "x", "y", "f", "g"], "name": "Simultaneous Equations with integers as solutions.", "tags": ["integer solutions", "linear equations", "simultanenous equations", "solving equations", "solving linear equations"], "advice": "", "rulesets": {}, "parts": [{"prompt": "

Solve the simultaneous equations:

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$\\simplify[all,!noLeadingMinus]{{a}x+{b}y = {f}}$

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$\\simplify[all,!noLeadingMinus]{{c}x+{d}y = {g}}$

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$x=\\;$[[0]]

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$y=\\;$[[1]]

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This question is set up by working \"backwards\" i.e. given the integer solutions for $x$ and $y$ and their coefficients gives the right-hand side of the equations.

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I have also insisted that the the coefficients in  both equations are coprime and that, in order not to get degenerate equations, the determinant of the coefficients is non 0. Look at Testing in Variables to see this.

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A simultaneous equations question with integers only

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