Three. x, y, and z. terms are the total different variables, not the total number of variables.
There are 3 units between y int. One is at y=0 and the other is y=-3
23=4w-13
36=4w
9=w
answer is w=9
33-7r = 3(6-4r)
33 - 7r = 18 - 12r
33 -7r + 7r = 18 - 12r + 7r
33 = 18 - 5r
33 - 18 = 18 - 5r - 18
15/5 = 5r/5
3 = r
r = 3