How do you multiply #(x + 1)(x - 1)^2#?

1 Answer
Jun 23, 2018

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

Explanation:

Let's focus on #(x-1)^2# first. This is equivalent to #(x-1)(x-1)#. So,

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

Now multiply this result by #(x+1)# and expand:

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