How do I factorise this?

[SuperTramp]

How do I factorise x^2 - 9 :confused:

Any help greatly appreciated

[Complex]

This is often called the difference of two squares

Anything of the form a^2 - b^2 can be factorised to (a-b)(a+b)

So x^2 - 9 = (x-3)(x+3)

Hope this helps

[SuperTramp]

Thanks Complex