Question

Find the value of n in the solution to the system of equations shown.

Answer 1

$\bf \begin{cases} \boxed{m}=5n-3\\ m=3n+7 \end{cases}\implies \boxed{5n-3}=3n+7\implies 2n=10 \\\\\\ n=\cfrac{10}{2}\implies n=5$

Answer 2

Subtract the second equation from the first.

... 0 = 2n -10

Divide by the coefficient of n.

... 0 = n - 5

Add 5.

... 5 = n . . . . the lower-left selection is appropriate