Wait, how can x be just 5? if it was justs 5, then we dont cut anything??
I'm not sure if my answer is correct if i do it like that...
What i did was:
V = x(10-2x^^2 + x^3
= 5x^3 - 40x^2 +100x
V' = 5(3x-10)(x-20 =0
x = 10/3 , 2
end points are x = 0 , x=5
when x = 0, V = 0
when x =2, V =80
when x=10/3 , V= 2000/27
when x = 5, V = 125
The maximum volume is when x =5 , but doesn't x = 5 mean that there were no squares cut, therefore, you cant really form a paper clip fold with top and bottom not closed? Doesn't the problem ask that there should be both items involved? or not?