Question

Simplify :(x+y+z)^2 + (x+y-z )^2?​

Answer 1

Sol.) (x+y+z)² + (x+y-z)²

= x² + y² + z² + x² + y² - z²

= x² + x² + y² + y² + z² - z²

= x⁴ + y⁴ (ANSWER)