Question

A stone is thrown upward, its height h meters after t seconds is given by this formular h=30t-5t². Find t when it is at a height of 25m, why are there two answers, what do they mean?

Answer 1

the answer is

T¹=5s

T²=1s

Am not sure about why there's two times , although perhaps the two times indicate the starting time and the other indicate the time when the stone hits 25m above the ground

Explanation:

the solving steps are in the picture.