Question

1. (x+y-z)-1;


2. x+(y-x);


3. (x+y)-(x-y);


4. (5x+7y)-(7x-5y);


5. (x-y+z)-(x+y-z

Answer 1

2)=у
3)=2у
4)=12у-2х
5)=2z-2y