Solve 8=8v-4(v+8), justifying each step with algebraic property.

8 = 8v -4v -32 . . . . . . distributive property (eliminated parentheses)
8 = (8 - 4)v -32 . . . . . distributive property‡ (factored out v)
40 = 4v . . . . . . . . . . . addition property of equality (added 32)
10 = v . . . . . . . . . . . . division property of equality (divided by 4)


‡ the associative property of addition may be in there, too.

AN ABOVE-GROUND SWIMMING POOL IN THE SHAPE
OF A CYLINDER HAS A DIAMETER OF 18 FEET AND A
HEIGHT OF 5.5 FEET. IF THE POOL IS FILLED WITH WATER
6 INCHES FROM THE TOP OF THE POOL, WHAT IS THE
VOLUME, IN TERMS OF PI, OF THE WATER IN THE POOL?