Answer
$(7, 15)$
or
$x = 7$
$y = 15$
Work Step by Step
$y = 5x - 20$
$2x - 3y = -31$
$2x - 3(5x - 20) = -31$
$2x - 15x + 60 = -31$
$-13x + 60 + 31 = 0$
$-13x +91 = 0$
$-13x = -91$
$x = 7$
$y = 5(7) - 20$
$y = 35 - 20$
$y = 15$
Check:
$2(7) - 3(15) \overset{?}{=} -31$
$14 - 45 \overset{?}{=} -31$
$-31 = -31$
$15 \overset{?}{=} 5(7) - 20$
$15 \overset{?}{=} 35 - 20$
$15 = 15$
