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A ball is thrown in the air from a ledge. Its height in feet is represented by f16(2-5x - 6), where x is the number of seconds since the ball has been thrown. The height of the ball is 0 feet when it hits the ground. How many şeconds does it take the ball to reach the ground?

A ball is thrown in the air from a ledge. Its height in feet is represented by f16(2-5x-example-1
User Darrin
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1 Answer

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Height in feet is represented by
f(x) = -16(x^2-5x-6)

The height of the ball is 0 feet when it hits the ground.

So we replace height f(x) by 0 and solve for x to find the time taken to reach the ground


f(x) = -16(x^2-5x-6)


0= -16(x^2-5x-6) ( divide by -16 on both sides)


0=(x^2-5x-6)

Now factor it

(x-6)(x+1) =0

x-6 =0 and x+1=0

x=6 and x=-1

Time cannot be negative so we ignore -1

x = 6 seconds

It will take 6 seconds for the ball to reach the ground.




User Shizoman
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