Factoring polynomials..

8

8dltndus

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I don't know what I did wrong for this question so please help me get the right answer on my own..


The height of a foot ball that has been thrown or kicked can be described by the expression
-16t+vt+h where t is the time in seconds, v is the initial upward velocity, and h is the initial height in feet.\

A. Write an expression for the height of the football at time when the initial upward velocity is 20 feet per second and the initial height is 6 ft.

answer:-16t+20t+6
I got this one right.

B.Factor your expression from part a. Check your answer.
answer:-2(-4t+1)(2t-3)
how did they get the -2 in front of the factoring?
I got (-4t+6)(4t+1)..:confused:


C.Find the height of the football after 1 second.
Answer:10ft.
..?

I got 8ft.





A little help would be greatly appreciated.
Thank you.
 
8dltndus said:
I don't know what I did wrong for this question so please help me get the right answer on my own..


The height of a foot ball that has been thrown or kicked can be described by the expression
-16t+vt+h where t is the time in seconds, v is the initial upward velocity, and h is the initial height in feet.\

A. Write an expression for the height of the football at time when the initial upward velocity is 20 feet per second and the initial height is 6 ft.

answer:-16t+20t+6
I got this one right.

B.Factor your expression from part a. Check your answer.
answer:-2(-4t+1)(2t-3)
how did they get the -2 in front of the factoring?
I got (-4t+6)(4t+1)..:confused:


C.Find the height of the football after 1 second.
Answer:10ft.
..?

I got 8ft.





A little help would be greatly appreciated.
Thank you.
Click to expand...

(-4t+6)(4t+1) is correct, but do you notice that in the factor (-4t+6) you can factor our a -2 and thus you get -2(2t-3)(4t+1) which is matches the correct answer.

Substitute in 1 in for t and you get -2(2-3)(4+1) = -2(-1)(5) = 10. Perhaps you made an arithmetic error.
 
8dltndus said:
The height of a [football] that has been thrown or kicked can be described by the [freefall] expression [-16t^2 + vt + h]
Click to expand...

No, it cannot.

I wish that I could have a personal moment with the author of this exercise. :roll:
 
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