Question 273305
x * (x - y - z) = x^2 - xy - xz (first part)


y * (x - y - z) = yx - y^2 - yz (second part)


since yx is the same as xy, this second part becomes:


y * (x - y - z) = xy - y^2 - yz (second part)


add first part and second part together and you get:


(x^2 - xy - xz) + (xy - y^2 - yz) which becomes:


x^2 - xy - xz + xy - y^2 - yz.


The + xy and the - xy cancel out so the equation becomes:


x^2 - xz - y^2 - yz


your answer was:


x^2 - 2x - y^2 - yz


not sure where you got the 2x from.


I believe that should have been zx or xz.