Answer:
Step-by-step explanation:
Answer:
The time taken for the flare to hit the ground is approximately 10.7 seconds.
Step-by-step explanation:
Given : Suppose a flare is shot from the top of a 120 foot building at a speed of 160 feet per second. The equation
models the h height at t seconds of the flare.
To find : How long will it take for the flare to hit the ground?
Solution :
The equation
models the h height at t seconds of the flare.
The flare to hit the ground when h=0.
Substitute in the equation,

Applying quadratic formula, 
Where, a=-16, b=160 and c=120





Reject the negative value.
Therefore, the time taken for the flare to hit the ground is approximately 10.7 seconds.
(2x-1)(x+4)=0
Step-by-step explanation:
A random zero property of multiplication is taken to find the solution
(2x-1)(x+4)=0
consider a=2x-1 and b=x-4 a.b=0
either a or b or both must be 0
equating both the equations
2x-1=0 or x=4=0 x-4=0
2x-1=0 x=4
2x=1
x=1/2
substitute the values of x in the main equation
[2(1/2)-1][(1/2)+4]=0