Question

(x + y + z)² - 2(x + y + z) (x + y) + (x + y)². Giup mình với nha!

Answer 1

\(\left(x+y+z\right)^2-2\left(x+y+z\right)\left(x+y\right)+\left(x+y\right)^2\)

= \(\left[\left(x+y+z\right)-\left(x+y\right)\right]^2\)

= \(z^2\)

Answer 2

Ta có:(x + y + z)² - 2(x + y + z) (x + y) + (x + y)²

=[(x+y+z)-(x+y)]²=z²