Chapter 7 - Polynomial Equations and Factoring - 7.5 - Factoring x 2 + bx + c - Exercises - Page 390: 53

$ z=-17$.

The given equation is $\Rightarrow z+12=-5$ Subtract $12$ from each side. $\Rightarrow z+12-12=-5-12$ Simplify. $\Rightarrow z=-17$ Check:- $z=-17$ $\Rightarrow -17+12=-5$ $\Rightarrow -5=-5$ True. Hence, the solution is $ z=-17$.