#1**0 **

Factor the following:

x^4-7 x^2-144

x^4-7 x^2-144 = (x^2)^2-7 x^2-144:

(x^2)^2-7 x^2-144

The factors of -144 that sum to -7 are 9 and -16. So, (x^2)^2-7 x^2-144 = (x^2+9) (x^2-16):

(x^2+9) (x^2-16)

x^2-16 = x^2-4^2:

(x^2+9) (x^2-4^2)

Factor the difference of two squares. x^2-4^2 = (x-4) (x+4):

**Answer: |(x-4) (x+4) (x^2+9)**

Guest Oct 21, 2016