Question

(x+y-z)-1
x+(y-x)
(x+y)-(x-y)
(x-y+z)-(x+y-z)
как их решить?

Answer 1

x+(y-x)= x+y-x=y
(x-y+z)-(x+y-z)=x-y+z-x-y+z= -2y+2z