Math Help - Trouble understanding simplification of algebraic statement

1. Trouble understanding simplification of algebraic statement

Hi all,

I am just working through an algebra example in a book and I can follow the multiple lines of simplification of the statement all of the way until the last line.

Without specifying why, it states:

And I just can't see how the right hand statement is derived from the left.
Can anyone shed any light?

2. Originally Posted by Iain
Hi all,

I am just working through an algebra example in a book and I can follow the multiple lines of simplification of the statement all of the way until the last line.

Without specifying why, it states:

And I just can't see how the right hand statement is derived from the left.
Can anyone shed any light?

They take out the common factor of $n_x^2$ in the last 2 terms, then rearrange the order they're written.
This is obtained by factorizing out the $n_x^2$ term