Step-by-step explanation:
Given the height of the rocket y in feet related to time after launch x related by the equation:
Y=-16x^2+189x+79
The rocket will hit the ground when y = 0
The equation will become:
0=-16x^2+189x+79
Rearrange
-16x^2+189x+79 = 0
multiply though by minus
16x^2-189x-79 = 0
Factorize and solve for x:
x = 189±√189²-4(16)(-79)/2(16)
x = 189±√35721+5056/32
x = 189±√40777/32
x = 189±201.93/32
x = 189+201.93/32
x = 390.93/32
x = 12.22secs
hence the rocket will hit the ground after 12.22seconds (to the nearest hundredth of a sec)