Our goal is to isolate x one side of the equation, which will lead us to the value of x.
First, add 73 to both sides to remove the -73 from the left side. (This will single out x with a constant.)
-2x - 73 = -89
Now, divide by -2 on both sides to remove the -2 coefficient on x.
-2x = -16
x = 8
We have our answer: x = 8.