Question

The equation - 5x² + 72x + 378 models the number of students enrolled in a school where x is the number of years since the school first opened in 1990. In which year were 502 students enrolled?

Answer 1

502=-5x^2+72x+378
-5x^2+72x+378-502
-5x^2+72x-124

Answer 2

using quadratic equation to find x\[x= {-b \pm \sqrt{b^2-4ac} \over 2a}\]

Answer 3

a=-5, b=72, c=-124

I got two solutions but the most likely is 2.

Answer 4

What year?

Answer 5

so most probably 1992

Answer 6

ok What if 598 students enrolled?

Answer 7

-5x^2+72x+378-598
-5x^2+72x-218

Answer 8

1998?

Answer 9

2000.

Answer 10

TY

Answer 11

oh and sorry for the late reply. Uhm 378-598=220.

Answer 12

yw.