Answer:
1: Simplify 15/20 to 3/4
y/4=3/4
Multiply both sides by 4
y=3/4×4
Simplify 3/4×4 to 12/4
y=12/4
Simplify 12/4 to 3
y=3
2: Multiply both sides by z-3
6=8/5(z-3)
Simplify 8/5(z-3) to 8(z-3)/5
8(z-3)/5
Multiply both sides by 5
6×5=8(z-3)
Simplify 6×5 to 30
30=8(z-3)
Divide both sides by 8
30/8=z-3
Simplify 30/8 to 15/4
15/4=z-3
Add 3 to both sides
15/4+3=z
Simplify 15/4+3 to 27/4
27/4=z Switch sides z=27/4