Simplify (x - y + z)2 - (x - y - z)2.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 4xz - 4yz.
⇒ (x - y + z)2 - (x - y - z)2
⇒ (x2 + y2 + z2 -2xy - 2yz + 2zx) - (x2 + y2 + z2 - 2xy + 2yz - 2zx)
⇒ x2 + y2 + z2 -2xy - 2yz + 2zx - x2 - y2 - z2 + 2xy - 2yz + 2zx
⇒ 4zx - 4yz