\(\left(x-y+z\right)-\left(k+z-y\right)\)
\(=x-y+z-k-z+y\)
\(=x+\left(-y+y\right)+\left(-z+z\right)-k\)
\(=x-k\)
(x - y + z) - (k + z - y)
= x - y + z - k - z + y
= x + (-y + y) + (z - z) - k
= x - k
(x-y+z) - (k+z-y)
=x-y+z-k-z+y
=(z-z)+(y-y)+x-k
=x-k
(x-y+z) - (k+z-y)
= x-y+z-k-k+y
= (-y+y)+ (z-z) + x-k
= x-k
Bỏ dấu ngoặc ta đc : x - y + z - k - z +y
\(\Rightarrow\)= x - k đó bạn