Question

Write in the expand form: `(2x - y + z)^2`

Answer 1

`(2x - y + z)^2 = [(2x) + (-y) + z]^2`

`= (2x)^2 + (-y)^2 + (z)^2 + 2(2x)(-y) + 2(-y)(z) + 2(2x)(z)`

`= 4x^2 + y^2 + z^2 + 4x(-y) - 2yz + 4xz`

`∴ (2x - y + z)^2 = 4x^2 + y^2 + z^2 - 4xy - 2yz + 4xz`