I get into so many arguments on here it's crazy, um ok bye.​

Ihonestly don’t understand this at all

Cindy uses 1-inch cubes to find the volume of a jewelry box shaped like a rectangular prism. she uses 780 cubes to completely fill the jewelry box with no gaps or overlaps. if the jewelry box is 13 inches long and 5 inches wide, how tall is cindy’s jewelry box?

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x