SOLUTION: Factor the trinomial. 4x^2-56x-92 I'm having problems figuring out this problem. The only numbers I can find that go into 92 are 4 and 23 but when I plug that in: 4x(-23)+4x=

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Question 701292: Factor the trinomial. 4x^2-56x-92
I'm having problems figuring out this problem. The only numbers I can find that go into 92 are 4 and 23 but when I plug that in:
4x(-23)+4x= -92x+4x=-88x. So it's not equaling -56x. I'm not sure what I'm doing wrong? Any help would be greatly appreciated! Thank you.
Found 2 solutions by jim_thompson5910, MathLover1:
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!

Start with the given expression.

Factor out the GCF .

Now let's try to factor the inner expression

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Looking at the expression , we can see that the first coefficient is , the second coefficient is , and the last term is .

Now multiply the first coefficient by the last term to get .

Now the question is: what two whole numbers multiply to (the previous product) and add to the second coefficient ?

To find these two numbers, we need to list all of the factors of (the previous product).

Factors of :
1,23
-1,-23

Note: list the negative of each factor. This will allow us to find all possible combinations.

These factors pair up and multiply to .
1*(-23) = -23
(-1)*(23) = -23

Now let's add up each pair of factors to see if one pair adds to the middle coefficient :

First Number Second Number Sum
1 -23 1+(-23)=-22
-1 23 -1+23=22

From the table, we can see that there are no pairs of numbers which add to . So cannot be factored.

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Answer:

So simply factors to

In other words, .

Answer by MathLover1(20850) (Show Source):
You can put this solution on YOUR website!

..... write as

....group first three terms together
....factor out
....note that