Question

Expand each of the following
using Suitable identities-
(3a-7b-c)²

(-2x+5y-3z) ²​

Answer 1

Step-by-step explanation:

Using Identity

(a+b+c)²=a²+b²+c²+2ab+2bc+2ac

{3a-7b-c}²={3a+(-7b)+(-c)}²

(3a)²-(7b)²-c²+2(3a)(-7b)+2(-7b)(-c)+2(3a)(-c)

9a²-49b²-c²-42ab+14bc-6ac

YOU CAN USE THE SAME IDENTITY TO SOLVE THE AKOTHER PROBLEM

Answer 2

1. 3a−7b−c)²

=(3a)² +(−7b)² +(−c)² +2(3a)(−7b)+

=(3a)² +(−7b)² +(−c)² +2(3a)(−7b)+2(−7b)(−c)+2(3a)(−c)

=(3a)² +(−7b)² +(−c)² +2(3a)(−7b)+2(−7b)(−c)+2(3a)(−c)=9a² +49b² +c² −42ab+ 14bc− 6ac

2. (−2x+5y−3z)²

=(−2x)² +(5y)² +(−3z)² +2(−2x)(5y)

+2(5y)(−3z) +2(−3z)(−2x)

=4x² +25y² +9z² −20xy −30yz +12xz