(х+у-z)-1 Х+(у-х) -х-(х-у+z) (А+b)-(a-b) (x-y+z)-(x+y-z) раскрытие скобок
1) (x+y-z)-1 = x+y-z-1 2) x+(y-x)= x - x +y = y 3) -x-(x-y+z) = -x-x+y-z=y-2x-z 4)(a+b)-(a-b) = a+b-a+b = 2b 5) (x-y+z)-(x+y-z) = x-y+z-x-y+z=2z-2y = 2(z-y)