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

$r=9.75$
The quantity inside of the parenthesis is being multiplied by -4. Thus, we first divide by -4 to find that $15.75=r+6$. We need to get the r alone. Thus, we cancel out the addition by subtracting 6 on both sides. This gives us the answer: $r=9.75$. We plug 9.75 in for r to check the answer and find that it is, indeed, correct.