ALGEBRA 2 HELP NEEDED ASAP!!!!!!

Assume h(x) = ax^2+bx+c
So you have for h(1) and h(2):

[1 1 1;4 2 1] * [a;b;c] = [186;344]

substract both lines of the number matrix.
c is cut from the equation so you have b=158-3a, and with this c=28+2a.

After this solve to find a, an you have b and c.
Now it's just do h(8) and i think it works.

Good luck

My attempt is not a textbook answer it is very crude:

Assume height h(0) = 0 ft
g = 32.2 ft/sec/sec

Unknown: Velocity at 0 seconds. called, V(0)

V(t) = -g*t + V(0) (from Wikipedia)

h(t) = -0.5*g*t*t + V(0)*t + h(0) (From Wikipedia)
substitute:
h(1) = 186 = -0.5*32.2*1*1 + V(0)*1 + h(0)
h(2) = 344 = -0.5*32.2*2*2 + V(0)*2 + h(0)
Subtract
h(2)-h(1) = 158 = -0.5*32.2*3 + V(0)
158+ 0.5*32.3*3 = V(0)
158 + 4830 = V(0) = 206.30 ft/sec
Therefore, at 8 seconds:
h(8) = -0.5*32.2*8*8 + 206.30*8 = 620.0 ft