Question

Factorize (2g)^2 - 18

Answer 1

2(2g^2-9)

Answer 2

using this identity a^2-b^2=(a+b)(a-b) is it possible to solve it

Answer 3

Yes, you can
\[18=(3\sqrt{2})^2\]
So we have
\[(2g)^2-(3\sqrt{2})^2\]
apply the identity as required!

Answer 4

or you can apply it after factoring out a 2
\[(2g)^2-18=4g^2-18=2(2g^2-9)=2((\sqrt{2}g)^2-3^2)\]