I dont understand how to solve a or b

In the past, professional baseball was played at the astrodome in houston, texas. the astrodome has a maximum height of 63.4 m. the height of a baseball t seconds after it is hit straight up in the air with a velocity of 45 ft/s is given by h = -9.8t2 + 45t + 1. will a baseball hit straight up with this velocity hit the roof of the astrodome? use the discriminant to explain your answer.

What is the expression in factored form? 225x^2 - 144 a. 9(5x+4)^2 b. 9(5x-4)^2 c. 9(4x+5)(4x-5) d. 9(5x+4)(5x-4)

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that