Factorise completely... (1 Viewer)

[Pororo]

Can someone please explain to me how that goes to something similar to this



I don't really understand the concept or the rule behind it.

 

[Shazer2]

This is an example of the "difference of two squares" rule where (a^2-b) when expanded is the same as (a-b)(a+b) given that b is a square number. So, the same rule applies here - both terms in the original equation are squared, so you can expand it to (a-b)(a+b), with (x^2+x)^2 being a and (x-3)^2 being b.

Hope this makes sense.

 

[Pororo]

Thanks it makes more sense now I'll have to note down your explanation. Thank you Shazer