Solve the following expression: 4 (r - 8 ) when r + 10

8
2
72
6

The answer is 8

Step-by-step explanation:

if R is equal to 10, the you subtract 10-8 which is two and multiply by four.

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)

2

step-by-step explanation: