Can Anyone Help Me With My Math Homework?

This is the surface area for a cuboid. To find out the height (h) you will have to know what the area, width and the length of the cuboid. If you have those values just put them in the equation and solve for h. The equation will become;
A=2lw + 2lh + 2wh
h(2l+2w) = A - 2lw
h = (A-2lw)/(2l+2w).

A = 2lw + 2lh + 2wh
A = 2(lw + lh + wh)
A = 2(lw) + 2(lh + wh)
A = 2(lw) + 2h(l+ w)
A/(l+w) = 2(lw)/(l+w) + 2h
A/(l+w) - 2(lw)/(l+w) = 2h
[A/(l+w)]/2 - (lw)/(l+w) = h

Greatest common factor
20 and 35