Solve what is the answer

-2z+3+7z=-12

-2z+3+7z=-12

⇒ (-2z + 7z) + 3 = - 12 (combine like terms)

⇒ 5z + 3 = - 12

⇒ 5z = - 12 - 3

⇒ 5z = - 15

⇒ z = - 15/5

⇒ z = - 3

Final answer: z = - 3.

Simple, all you want to find is z. Thus, you will isolate the variable z and move everything else to the other side. So when you do that the equation will look like, 5z=-15. Then just divide by 5 and your answer is z=-3.