Answer:
8
Step-by-step explanation:
volume of a cylinder is pi r^2 h
401.92/3.14=128
we only can make the height 2.
128/2=64
square root of 64 is 8
8 is the answer.
-- Do anything you need to do in order to get 'x' all by itself on one side and everything else on the other side.
-- As soon as you do anything to one side of the equation, you must immediately do the same thing to the other side.
-- That's the whole book on solving any equation with a single variable.
We have 5 friends that eat a half pizza, the portion each one eats is:

We have to divide by 5 the 1/2 pizza.
I think that the answer would be 5x20=100 and 5x4=20 so 100 + 20 = 120