A ball is projected upward from the ground. It’s distance in feet from the ground in t seconds is given by s(t)=-16t squared +124t. At what times will the ball be 225 feet from the ground ?

as shown

Step-by-step explanation:

d = -16t^2+124t        d= 225 feet

225 = -16t^2 +124 t

225 = -16(t^2 -7.75t))

do that perfect square thing   7.75/2   squared... =15.015625

225 = -16 ( t^2 - 7.75t +15.015625)   +(16)(- 15.015625)

225 = -16 ( t-15.015625)^2 -240.25

465.25 = -16 (t -15.015625)^2

29.078 =(t -15.015625)^2

5.39 =t -15.015625

20.405625 = t

in seconds of course

:)

b is the right answer