Find an expression, in terms of n, for the nth term in this sequence 2 6 12 20 30

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.

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Ill mark the brainliest if you me with the these three questions 7,8,9