Y = -x- + 4x + 4
Write in vertex form

and it's linearjddjdndkfkkdkd

-1,4

Imagine taking a soup can and peeling off the label. This label fully covers the curve side. What comes off is a flat piece of paper. If no tears are made, you'll have a rectangle after its fully peeled off.

The rectangle will have a width of W = 50 (same as the height of the can) and a length of L = 2*pi*r (same as the circumference of the base). So the area of this rectangle is A = W*L = 50*2*pi*r = 100*pi*r

The expression 100*pi*r represents the lateral surface area for this particular cylinder

We are given that the lateral surface area is 750 square inches, so this is the area of the label that peels off meaning A = 750

Equate the two values and solve for r
100*pi*r = 750
pi*r  =750/100
pi*r = 7.5
r = 7.5/pi
r = 7.5/3.14
r = 2.3885
which rounds to 2.39

This is why the answer is choice B) 2.39 inches