3x + 12y = -15 and it is infinite i just don't how to solve it

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?

What is the upper quartile in the box plot?

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.