Question

1. $-3r - 36 = -15$

Explanation:

Step1: Add 36 to both sides

$-3r - 36 + 36 = -15 + 36$
$-3r = 21$

Step2: Divide by -3 on both sides

$\frac{-3r}{-3} = \frac{21}{-3}$

Answer:

$r = -7$