The recursive formula for a pyramidal sequence is P(n) = P(n – 1) + n2. A stack of cannonballs with 7 layers has 140 balls. A stack with 8 layers has 140 + 82 = 204 balls. Find the number of cannonballs in a stack that has 10 layers.

You have a square piece of cardboard that measures 14 inches on each side. to build a box, you cut congruent squares out of each corner of the cardboard. use the picture to find the area of the cardboard you were used to build the box