Question

Help me pls!Could u explain how to do it!In a simple way thanks!

Answer 1

a) (x-c)²
= x²-2cx+c²
1. x×x = x²
2. 2×x×(-c) = -2cx
3. (-c)×(-c) = c²

b) (a-2b-c)²
= (a-2b-c)(a-2b-c)
= a²-2ab-ac-2ab+4b²+2bc-ca+2bc+c²
= a²-4ab-2ac+4b²+4bc+c²