The expression 16t² models the distance in feet that an object falls during t seconds after being dropped. What distance will an object fall in 4 seconds?

a. 128 ft

b. 256 ft

c. 32 ft

d. 1024 ft

Solve: C = π/d for d.

a. C = π/d

b. d = C/π

c. d = π/C

d. d = πC

Name the property of real numbers illustrated by the equation ( x + 8 ) + 4 = x + (8 + 4).