(3/4)x - 9 = 27
Isolate the x. Note the equal sign. What you do to one side, you do to the other. Do the opposite of PEMDAS.
First, add 9 to both sides
(3/4)x - 9 (+9) = 27 (+9)
(3/4)x = 36
Next, to isolate the x, multiply 4/3 to both sides
(4/3)(3/4)x = 36(4/3)
x = 36(4/3)
x = 48
48 is your answer
hope this helps