How do you expand brackets?

The easiest method to expand brackets would be to remember FOIL!
F - First
O - Outside
I - Inside
L - Last

Okay, so lets say you want to expand (3x+1)(2x+3), we'll fist multiply the first term of each bracket, 3x2x, which gives us 6x². Next the outside term of each, 3x3, which makes 9x. Then the inside terms which are 12x, making just 2x. Finally the last terms, 31 which is just 3.
Adding these four together we get:
6x²+9x+2x+3
We can simplify the two x terms to leave us with a final answer of:
6x²+11x+3