Ex: solve for x
x+3=7 since I want to get x by itself i remove the three.
x+3-3=7-3 The opposite of plus 3 is minus 3, and whatever I do to one side i MUST do to the other side, so you want to subtract 3 from both sides.
x=4 so, 3 minus 3 = 0 and 7 minus 3 = 4.