Check the picture.
let the length of a side of each of the squares removed be x.
The box formed will have dimensions: 80-2x, 50-2x, x(the height)
So the volume can be expressed as a function of x as follows:
f(x)=(80-2x)(50-2x)x=
![[4000-160x-100x+4 x^{2} ]x=(4 x^{2}-260x+4000)x](https://tex.z-dn.net/?f=%5B4000-160x-100x%2B4%20x%5E%7B2%7D%20%5Dx%3D%284%20x%5E%7B2%7D-260x%2B4000%29x)
so

the solutions of f'(x)=0 gives the inflection points, so the candidates for maxima points,

solving the quadratic equation, either by a calculator, graphing software, or by other algebraic methods as the discriminant formula, we find the solutions
x=10 and x=33.333
plug in f(x) these values to see which greater:

cm cubed

which is negative because (50-66.666)<0
Answer: 18000 cm cubed
First, we must solve for the radius of the sphere:
V=



r=(3

)

r=(3*

)

r≈5.99
Second, we must solve for surface area:
A=4


A=4*

*

A≈450.88
On the 14 week Juan will save $ 52 because each 3 week he earns 3.
So you do 9 divide by 3 and get 3. Then you do 3 times 2 and get 6.
46 + 6 = 52
~JZ