Question

Someone please please help me with these last five problems..

Answer 1

the first one find the surface area and volume of a larger solid.
and the other 2 pictures for all four, find the surface area and volume of a larger solid.

Answer 2

In each one solve for the surface area or volume of the object - ex. for your first one the surface area is 48*pi right? The surface area of a cylinder is 2*pi*r*h=48*pi.
Now replace each of the dimensions by the scaling factor times itself --> r=2/3r and h=2/3h.
Then all you need to do is rearrange until you get the original (2*pi*r*h) equation back and the right side is the answer.

Answer 3

Whoa oops that's wrong, you need to add the top and bottom of the cylinder as well.
So 2*pi*r*h+2*pi*r^2.
Same from there on though.

Answer 4

for the first pic. i got the SA=108pi cm^2 and volume 1215pi/8 cm^3

Answer 5

SA is right you should check your second though - \[45\pi=\pi*r^2*h=\pi*(2/3)^2*r*2/3*h=2/3^3*\pi*r^2*h\]
so then solve to get the original equation back and you get 45*27/8 which is some fraction around 150 I don't have a calculator on me