x+36=83
we nee to leave X by itself, in order for us to do that we need to take away the 36.
to take away the 36 all we need to do is the opposite of what is being done, which is in this case is subtraction since what is being done is addition (+36)
X+36=83
-36 -36 (what you do on one side of the parenthesis must be done on the other in order to balance the equation)
X=47