The question is to find the first three terms of (1-9x+x^2)^5. It has a hint provided which says: 'Write it as (1-9x(1-x/9))^5 and use the binomial theorem.'

The problem is when using the binomial equation, how should I split it up? What should be my 'x' and what should be my constant?

(Sorry, Latex doesn't work at the moment, so it might appear a bit messy)