(3x + 1)2 - x2
How do you say it?
So this is pronounce ‘bracket three x plus one bracket square minus x square?
Not sure how exactly they would say it in the UK, but here's yet another mathematically legal way to verbalize that:
Three x plus one quantity squared minus x squared.
So, you list out one by one all the things that you have in parentheses and then to indicate that you want to square all of what you just listed out, you just say quantity squared or entire quantity squared and follow that with the rest of your math expression.
A more traditional way of saying it would be:
Open parenthesis three x plus one close parenthesis whole thing squared minus x squared.