Question

240=200+30t-5t^2

find t

Answer 1

240=200+30t-5t^2
240-200=30t - 5t^2
40=30t-5t^2

5t^2 - 30t + 40 = 0

divide by 5

t^2 - 6t + 8= 0

t^2 - 4t - 2t + 8 = 0

t(t-4)-2(t-4)=0
(t-2)(t-4)=0

therefore, t is either 4 or 2..

Answer 2

thanks a lot!!

Answer 3

:)