Hi!
The only like terms in the equation are 16x and -4x because they both have x as a coefficient.
Like terms would not be something like 25 and 8x.
When you combine like terms, you solve them like normal.
16x - 4x = 12x
The answer is 12x = -48
If you want me to solve for x, here you go:
Divide by 12 on both sides.
12x/12 = -48/12
x = -4
Hope this helps! :)
-Peredhel