Question 291837
10x^4 - 160  ...first factor out 10

so:
(10)(x^4 - 16)  now you have the difference between two squares

SO:

(10)(x^2 - 4)(x^2 + 4) ..you can go farther and do the difference between squares again.

(10)(x - 2)(x + 2)(x^2 + 4)

Does that help