Question

9(2a+b)^2 - 4(a-b)^2 Factorise using identities​

Answer 1

Answer:

Given : 9(2a−b)  

2

−4(2a−b)−13

Let us consider 2a−b=c

So we get,

=9c  

2

−4c−13

We can further write it as  

=9c  

2

−13c+9c−13

By taking out the common terms

=c(9c−13)+1(9c−13)

=(c+1)(9c−13)

Let us replace c by 2a−b

so we get

9(2a−b)  

2

−4(2a−b)−13

Then,

=((2a−b)+1)(9(2a−b)−13)

∴9(2a−b)  

2

−4(2a−b)−13=(2a−b+1)(18a−9b−13)