Answer
$x=-10$
Work Step by Step
$x-12=-45+23\rightarrow$ simplify
$x-12=-22\rightarrow$ add 12 to both sides
$x-12+12=-22+12\rightarrow$ simplify
$x=-10$
Check the solution by plugging in the value for y and determine whether the resulting equation is true.
$-10-12=-45+23\rightarrow$ simplify
$-22=-22$
This is true so the solution is correct.