Factorise x³-x²-x+1?

2 Answers
May 21, 2018

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

Explanation:

#x^3 - x^2 - x + 1#

To factor this, we have to do it by grouping terms:
#(x^3-x^2) + (-x+1)#
To factor #x^3 - x^2#, we have to see the greatest factor that both expressions have in common. In this case, that is #x^2#. So the factored form would be:
#x^2(x-1)#

For the second part, we want #-x# to be positive, so we can factor out a #-1#:
#-1(x-1)#

Now combine them:
#x^2(x-1)-1(x-1)#

This becomes:
#(x^2-1)(x-1)#

If you want, you can still factor this further since #(x^2-1)# can split out to be #(x-1)(x+1)#. So the factored form is:
#(x-1)(x+1)(x-1)#

Hope this helps!

May 22, 2018

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

Explanation:

#x³-x²-x+1#

#(x³-x²)+(-x+1)# separate the terms

#(x³-x²)-1(x-1)# factor out #-1#

#x^2(x-1)-1(x-1)# factor out #x^2#

#(x-1)(x^2 -1)# factor by grouping, factor out #x-1#

#(x+1)(x -1)(x-1)# difference of squares

#(x - 1)^2 (x + 1)# combine like terms