Question

2m + 5n = 12
6m - 15n = -51

Answer 1

$2m + 5n = 12 \\ 2m = 12 - 5n \\ m = \frac{12 - 5n}{2}$

$6m - 15n = - 51 \\ 3(2m - 5n) = - 51 \\ 2m - 5n = - \frac{51}{3} \\ 2m - 5n = - 17 \\ 2m = - 17 + 5n \\ 2m = 5n - 17 \\ m = \frac{5n - 17}{2}$


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