Question

What is the following solution to |x+3|=12

Answer 1

$|x+3|=12\\ x+3=12 \vee x+3=-12\\ x=9 \vee x=-15$

Answer 2

$|x|=a\iff x=a\ or\ x=-a\\==============================\\|x+3|=12\iff x+3=12\ or\ x+3=-12\ \ \ \ |subtract\ 3\ from\ both\ sides\\\\\boxed{x=9\ or\ x=-15}$