How do you factor #x^3+3x^2-x-3=0#?
1 Answer
Dec 28, 2015
Alternatively, you can factor by grouping and using the difference of squares identity to find:
#x^3+3x^2-x-3=(x-1)(x+1)(x+3)#
Explanation:
The difference of squares identity can be written:
#a^2-b^2 = (a-b)(a+b)#
Factor by grouping then using the difference of squares identity with
#x^3+3x^2-x-3#
#=(x^3+3x^2)-(x+3)#
#=x^2(x+3)-1(x+3)#
#=(x^2-1)(x+3)#
#=(x^2-1^2)(x+3)#
#=(x-1)(x+1)(x+3)#
