C1 help

Hi
I haven't understood how to do these types of questions, could someone give a step by step answer please? thanks
"Express (2- √3)² in the form b + c√3, where b and c are integers to be found"
Thanks so much

Consider this:

(2- √3)² is the same as (2- √3)(2- √3)

From there, you just use FOIL to multiply out the brackets. And don't worry, you will end up with an answer in the form b + c√3 (unless you're using a calculator, in which case, you'd end up being kicked out of the C1 exam, anyway .)

hi
I have expanded the brackets, that wasn't a problem but now I have 7-4√3, yet the question is asking for an answer as b + c√3. How do I proceed?

That's the right answer, since b and c can be either positive or negative, unless the question specifically states otherwise, so in this case, c is -4.