Question

using standard formulae, expand the following (x-2y-z)²​

Answer 1

Answer:

x²+4y²+z²-4xy+4yz-2xz

USING (A+B+C)² IDENTITY.

HOPE IT HELPS.....

Answer 2

Answer:

I guess you shud use the formula: (a+b+c)² but use the minus‐ sign instead of plus+