When solving this equation, you get the answer as -43.5.
To solve, we simply need to collect like-terms and then rearrange to get x on one side and numbers on the other:
(8x - 20) - 16 = 10x + 51
8x - 36 = 10x + 51
- 8x
-36 = 2x + 51
- 51
-87 = 2x
÷ 2
-43.5 = x
I hope this helps!