How do you factor completely #2x^5 - 7x^3 - 4x#?

1 Answer
Jul 17, 2016

Answer:

#(2x^2 +1)(x+2)(x-2)#

Explanation:

Take out the common factor of #x# first.

#x(2x^4 -7x^2 -4)#

We now have a disguised quadratic, but we treat it the same as a quadratic.

Find factors of 2 and 4 which subtract to make 7.

#"2 +1 "rArr " 1 x 1 = +1"#
#"1 -4 "rArr " 2 x 4 = -8 " rArr -8+1 =-7#

#(2x^2 +1)(x^2 -4)#
#(2x^2 +1)(x+2)(x-2)#