Find the surface area of the sphere in terms of pi

A = 225π in²

Step-by-step explanation:

The equation for the surface area of a sphere is:

A = 4πr²

Plug 7.5 in for r (since r = d/2):

A = 4π(7.5²) = 4π(56.25) = 225π

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18