Question #964f3
1 Answer
Aug 14, 2014
These are the same expressions, just written differently. To prove this, just multiply the terms out and you'll end up with the same expression.
Let's start by multiplying the first equation:
#(x+1)^3-5x-5#
#=(x+1)(x+1)(x+1)-5x-5#
#=(x^2+2x+1)(x+1)-5x-5#
#=x^3+x^2+2x^2+2x+x+1-5x-5#
#=x^3+3x^2-2x-4#
Now let's do the second equation:
#(x+1)(x^2+2x-4)#
#=x^3+x^2+2x^2+2x-4x-4#
#=x^3+3x^2-2x-4#
As you can see, these are the same!
