Answer:
You shouldn't blame your mom. You are more than capable of getting 80's that is the bare minimum. Your mom does not want you to fail, try harder and get better grades. 70's are not the best
(4x-3y)^2(4x-3y)
=(16x^2-24xy+9y^2)(4x-3y)
=64x^3-96x^2y+36xy^2-48x^2y+72xy^2-27y^3
=64x^2-144x^2y+108xy^2-27y^3
There is a common ratio of 2/3 between the height of the ball at each bounce. So, the bounce heights form a geometric sequence: 27, 18, 12. Two-thirds of 12 is 8, so on the fourth bounce, the ball will reach a height of 8 feet.