Question

The expansion of(x+y-z)^2

Answer 1

x²+y²+z²+2xy-2yz-2zx

Explanation:

{(x+y)-z}^2

=(x+y)²-2(x+y)z+z²

=x²+2xy+y²-2zx-2yz+z²

=x²+y²+z²+2xy-2yz-2zx