25 = -16t^2 + 50t + 4
16t^2 - 50t + 21 = 0
16t^2 - 8t - 42t + 21 = 0
8t(2t - 1) - 21(2t - 1) = 0
(8t - 21)(2t - 1) = 0
8t - 21 = 0 or 2t - 1 = 0
t = 21/8 or t = 1/2
t = 2.625 or t = 0.5
X < -3.909091
*round if you want to*
B is the best way to slow the greenhouse effect