You gave little context, so here is a few solutions.
POSSIBLE #1:
assuming s is a variable
---> Simplify ×
to
---> Collect like terms.
---> Simplify.
POSSIBLE #2: (assuming s is not relevant)
Simplifying
4x + -12 = 16 + 8x
Reorder the terms:
-12 + 4x = 16 + 8x
Solving
-12 + 4x = 16 + 8x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-8x' to each side of the equation.
-12 + 4x + -8x = 16 + 8x + -8x
Combine like terms: 4x + -8x = -4x
-12 + -4x = 16 + 8x + -8x
Combine like terms: 8x + -8x = 0
-12 + -4x = 16 + 0
-12 + -4x = 16
Add '12' to each side of the equation.
-12 + 12 + -4x = 16 + 12
Combine like terms: -12 + 12 = 0
0 + -4x = 16 + 12
-4x = 16 + 12
Combine like terms: 16 + 12 = 28
-4x = 28
Divide each side by '-4'.
x = -7
Simplifying
x = -7
If there are any other ways to solve this please add more context in the comments below this answer! Hope this was helpful! Have a marvelous day/night!