Раскройте скобки. 1. (x+y-z)-1 2. x+(y-x) 3. (x+y)-(x-y) 4. (x-y+z)-(x+y-z)

1. (x+y-z)-1=x+y-z-1 2. x+(y-x)=x+y-x=y 3. (x+y)-(x-y)=x+y-x+y=2y 4. (x-y+z)-(x+y-z)=x-y+z-x-y+z=2z-2y