## Algebra 1: Common Core (15th Edition)

$r=6$
The distributive property allows us to distribute anything multiplied by something inside of the parenthesis to whatever is inside of the parenthesis. Thus, we distribute the 8 to everything inside the parenthesis, giving us the equation $8r+16=64$. We now need to get the r alone. Thus, we cancel out the addition by subtracting 16 on both sides. This leaves us with the equation $8r=48$. In order to cancel out multiplication, we use division, so we divide both sides by 8 to get that $r=6$. We plug 6 in for r and confirm that our answer is, indeed, correct.