For every real number x, y, and z the statement (x-y) z=xz-yz is

true.

Step-by-step explanation:

(x - y) z = xz - yz

Apply the distributive property of multiplication over addition to the left side:

(x - y) z =

= z (x - y)

= xz - yz

This is the same as the right side, so the statement is true.