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

$z=-10$
We need to get the z alone. Thus, we cancel out the subtraction by adding 4 on both sides. This leaves us with the equation $-z=10$. In order to cancel out multiplication, we use division, so we divide both sides by -1 to get that $z=-10$. We plug -10 in for z and confirm that our answer is, indeed, correct.