Question

solve the absolute value 3[z+7]=-12

Answer 1

Two is the answer because 3+2=5+7=12.So the missing number is 2.

Answer 2

$3|z+7|=-12\\|z+7|=-4\\\\z+7=-4\\z+7=4\\\\z=-11\\z=-3\\\\\\\sf{Plug~them~to~test~if~the~solution~is~correct.}\\\\ 3|-3+7|=-12 \\ 3 (4)\neq -12 \\ \\ 3 |-11+7|=-12\\ 3 (4)\neq-12 \\ \\ \\ \boxed{\sf{There~is~no~solution.}}$