-3x - 3/4 = 9
-3x - 3/4 + 3/4 = 9 + 3/4
-3x = 9 3/4
I change 9 3/4 to improper fraction
-3x = 39/4
-3x / -3 = 39/4 / -3
X = 39/4 x -1/3 (change division to multiplication so that you can complete the problem)
X = -39/12
You can convert that if you want to -3 3/12
So x = -3 3/12
Simplify to x = -3 1/4