Question

Can someone show me how to do this problem?

Answer 1

You need to keep the number less than 250 so we can write the equation as
250 = 20t² -25t +100
which equals
20t² -25t -150
we can solve this from the quadratic formula:
t = [--25 +-sqroot(625 -4*20*-150)] / 2*20
t = 25 +-sqroot(625 +12,000) / 40
t = 25 +-sqroot(12,625) / 40
t = 137.36 / 40
t = 3.434

So, I'd say the answer is d

Answer 2

Thank you!

Answer 3

Could you tell me where you got the 625 from?

Answer 4

625 is 25^2

Answer 5

because the quadratic formula is