How do you factor 2x^3 + x^2- 6x- 3?

1 Answer
Jul 21, 2015

Factor by grouping to find:

2x^3+x^2-6x-3

= (x^2-3)(2x+1)

= (x-sqrt(3))(x+sqrt(3))(2x+1)

Explanation:

Factor by grouping, then use difference of squares identity:

a^2-b^2 = (a-b)(a+b)

as follows:

2x^3+x^2-6x-3

=(2x^3+x^2)-(6x+3)

=x^2(2x+1)-3(2x+1)

=(x^2-3)(2x+1)

=(x^2-(sqrt(3))^2)(2x+1)

=(x-sqrt(3))(x+sqrt(3))(2x+1)