Is this factorable???

The directions say to factor but I am not sure if the problem is factorable or not.Any directions or advice would be fully appreciated.


Here is the problem: 18+7x^2-x^4




Thank you for putting your time and effort in helping me with this problem.

the expression is quadratic in x² ...

let u = x²

18 + 7x² - x⁴ = 18 + 7u - u²

the right side will factor ... back substitute x² for u when you're done.

JOSE JAIME-RODRIGUEZ said:

The directions say to factor but I am not sure if the problem is factorable or not.Any directions or advice would be fully appreciated.
Here is the problem: 18+7x^2-x^4

Click to expand...

Start by changing the signs (or multiplying by -1):
x^4 - 7x^2 - 18 ; now simply factor:
(x^2 - 9)(x^2 + 2)

Thank you Denis and Skeeter I could now finish this problem.Thank you for your help