How do you simplify #(x-y+1)-(x+y-1)#?

2 Answers
Sep 10, 2016

#-2y+2#

Explanation:

The terms in the 1st bracket are being multiplied by 1 , while each of the terms in the 2nd bracket are being subtracted.

That is #1(x-y+1)-x-(+y)-(-1)#

simplifying gives.

#x-y+1-x-y+1#

and collecting like terms.

#cancel(x)+(-y-y)+(1+1)cancel(-x)=-2y+2#

Sep 10, 2016

#2 - 2 y#

Explanation:

We have: #(x - y + 1) - (x + y - 1)#

Let's expand the parentheses:

#= x - y + 1 - x - y + 1#

Then, let's group the like terms:

#= (x - x) + (- y - y) + (1 + 1)#

#= 0 - 2 y + 2#

#= 2 - 2 y#