Question

evaluate the following

(2x+y-z)^2

Answer 1

${ (2x + y - z)}^{2} \\ = {(2x)}^{2} + {(y) }^{2} + {( - z)}^{2} + 2 \times 2x \times y + 2 \times y \times ( - z) + 2 \times ( - z) \times 2x \\ = 4 {x}^{2} + {y}^{2} + {z}^{2} + 4xy - 2yz - 4zx$