Hi there!
Okay, so we are solving for s. This is pretty simple. Just follow the steps below!
-10s = -8 - 9s
Step 1) Simplify both sides of the equation.
-10s = -8 + - 9s
-10s = -9s - 8
Step 2) Add 9s to both sides.
-10s + 9s = -9s - 8 + 9s
-s = -8
Step 3) Divide both sides by -1.
-s/-1 = -8/-1
s = 8
Our final answer is s = 8.
Hope this helps!