Question

Jenny used the expression –16x2 + 38x + 5 to determine the height of an object x seconds after it was hit into the air. How long does it take the object to hit the ground?

Answer 1

0<x<2.5

Explanation:

-16x^2+38x+5 = 0

-16x^2+40x-2x+5 = 0

ROUGH WORK

[Product=-16×5=-80, Sum=38. (Product=40×-2, Sum=40-2) (40&-2)]

BACK TO EXPLAINATION

-8x(2x-5)-1(2x-5) = 0

x = -1/8, 2.5

0<x<2.5