Please help ! in class and don't understand!

Me. drysdale earned 906.25 in interest in one year on money that he had deposited in his local bank if the bank paid an interest rate of 6.25% how much money did mr. drysdale deposit

The base of a triangle exceeds the height by 7 centimeters. if the area is 400 square centimeters, find the length of the base and the height of the triangle.

Which of the binomials below is a factor of this exression? 16x^2+40xy+25y^2 a.4x-5y b. 2x-5y c.4x+5y d.2x+5y