Cant find GCF

G

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Factor 18+7x^2-x^4


I know you are suppose to find the greatest common factor but I cant find one in 18+7x^2-x^4. What do I do since there is no GCF???
 
Where did you get the idea that you need a common factor?
 
in my book it explains that you need to look for a common factor first
 
Too bad so sad...you're probably looking in the wrong spot...

You need to learn how to factor.
Can you factor this: x^2 + 3x - 10
 
brianpadilla said:
.......(x-2)(x+5).........
CORRECT! So do you see a "common factor"? I don't.

18+7x^2-x^4
OK; make it easier by multiplying by -1:
x^4 - 7x^2 - 18 : get that?
= (x^2 - 9)(x^2 + 2) : ok? same way as you got (x-2)(x+5).

Now, you can factor x^2 - 9, right?
(x - 3)(x + 3)

So you end up with:
(x^2 + 2)(x - 3)(x + 3)
 
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