Answer:
x/2 + 21 = 36
First we get rid of constants to isolate the variable.
In order to do that we must do the inverse operation.
Inverse operation of addition is subtraction.
-21 -21(subtracting 21 from both sides, whatever we do to the left side we do it to the right side too)
x/2 = 15
inverse property of division is multiplication
x2 x2
X = 30