Answer:
4 seconds.
Step-by-step explanation:
The given equation is
where, h is height in feet of a golf ball above the ground after being hit into the air and t is the number of seconds elapsed since the ball was hit.
We need to find the time for the ball to hit the ground.
At ground level the height of ball is 0, i.e., h=0.
Using zero product property, we get
Therefore, it will take 4 seconds for the ball to hit the ground.
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Explanation:
I'll use the quadratic formula to find the roots or x intercepts. This slight detour allows us to factor without having to use guess-and-check methods.
The equation is of the form ax^2+bx+c = 0
This leads to...
Now use those roots to form these steps
Refer to the zero product property for more info.
Therefore, the original expression factors fully to (4x-5)(3x+1)
Use the FOIL rule to expand it out and you should get 12x^2-11x-5 again.
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We did that factoring so we could find the side lengths of the rectangle.
I'm using the fact that area = length*width
The order of length and width doesn't matter.
From here, we can then compute the perimeter of the rectangle
P = 2(L+W)
P = 2(4x-5+3x+1)
P = 2(7x-4)
P = 14x - 8