Expanding and Factorising Basics
Single brackets are your starting point and they're actually quite straightforward. You simply multiply the number outside the bracket with every term inside. For example, 4a+1 becomes 4a+4, and -3b+2 becomes -3b-6.
Double brackets need a bit more strategy, but you've got two reliable methods to choose from. The FOIL method stands for First, Outside, Inside, Last - so for x+2x−5, you multiply x×x, then x×(-5), then 2×x, and finally 2×(-5). This gives you x²-5x+2x-10, which simplifies to x²-3x-10.
The grid method works just as well and some students find it clearer. Draw a 2×2 grid, put your bracket terms along the top and side, then multiply each pair to fill the boxes. Both methods give you the same answer!
Top tip: Always collect like terms at the end - it's easy to forget this step but it's crucial for getting full marks.
Triple brackets might look scary, but they're just double brackets with an extra step. Expand the first two brackets, collect like terms, then multiply your result by the third bracket. Take your time and work methodically - rushing leads to silly mistakes.