An open box is to be constructed from a square piece of sheet metal by removing a square of side 5 feet from each corner and turning up the edges. (See the figure on the right.) If the box is to hold 720 cubic feet, what should
be the dimensions of the sheet metal?

Helll ! 1,400 tons of wheat of two different varieties was delivered to the silo. when processing one variety, there was 2% of waste and 3% during the processing of the second variety of wheat. after the processing, the amount of remaining wheat was 1,364 tons. how many tons of each variety of wheat was delivered to the silo?