Answer:
Step-by-step explanation:
[tex]5x^{4} -30x^{2} -135[/tex]
We need to pull out 5 to make the rest easier to factor.
[tex]5(x^{4} -6x^{2} -27)[/tex]
Now we can factor.
Consider all combinations of how to get 27.
1 x 27
3 x 9
And that's it before you end up just switching the place i.e. 9 x 3 and 27 x 1
This makes it easy to see that 3 and 9 are our best choice because 9 - 3 is 6 which is our middle term in the equation.
So now we have:
[tex]5(x^{2} -9)(x^{2} +3)[/tex]
We can break down [tex]x^{2} -9[/tex] even further because it's a perfect square.
(x - 3)(x + 3)
Our final factor is
5(x - 3)(x + 3)[tex](x^{2} +3)[/tex]