SOLUTION: b. Try the above method to factor x^2 &#8722;2x &#8722;8 . Why is it difficult to find the correct factors for this trinomial using this method? I already know the answer to B.

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Question 1095933: b. Try the above method to factor x^2 −2x −8 . Why is it difficult to find the correct factors for this trinomial using this method?
I already know the answer to B.
x^2 - 2x-8
(x^2 +2x) +(-4x - 8)
= x(x+2)-4 (x+2)
= (x+2) (x-4)

c. Evaluate the expression in part b for x=7 . Then use the above method to find the factors.
Explain each step. Remember in finding your factors that x=7

I'm having trouble with question C.
Answer by josgarithmetic(39625) (Show Source):
You can put this solution on YOUR website!
Much of what you wrote is disconnected.

You wish to factorize .
The constant term based on 1 and 8 will not work.
The constant term based on 2 and 4 may work.

Fill in the necessary parts for this format for constants m and n:

(x m)(x n)

The factorization which will work is , which you could check by doing the multiplication and simplifying.

SOLUTION: b. Try the above method to factor x^2 &#8722;2x &#8722;8 . Why is it difficult to find the correct factors for this trinomial using this method? I already know the answer to B.

SOLUTION: b. Try the above method to factor x^2 −2x −8 . Why is it difficult to find the correct factors for this trinomial using this method? I already know the answer to B.