act. 3 las trollecitas

1° x+4=28
x=28-4
x=24

2° y-6.5=31
y=31+6.5
y=37.5

3°8z=40+3z
8z-3z=40
5z=40
z=8

4°10x=-5x+60
10x+5x=60
15x=60
x=4

5° -15y+3=-36-18y
-15y+18y=-36-3
+3y=-39
y=-13 ...