By using standard formulae, expand the following:

(2x - 3y + 4z)²

(2x - 3y + 4z)² = [(2x) + (-3y) + (4z)]²

= (2x)² + (-3y)² + (4z)² + 2 [(2x)(-3y) + (-3y)(4z) + (4z)(2x)]

= 4x² + 9y² + 16z² + 2[-6xy - 12yz + 8xz]

= 4x² + 9y² + 16z² - 12xy - 24yz + 16xz