Question

Solve for r: -5 = 7 + 3r

Answer 1

$-5=7+3r\ \ \ \ \ \ |combine\ like\ terms\\\\-5-7=3r\\\\-12=3r\ \ \ \ \ \ \ |:3\\\\r=-4$

Answer 2

So,

-5 = 7 + 3r
(subtract 7 from both sides)
-12 = 3r
(divide both sides by 3)
-4 = r