# Double brackets

Multiplying two brackets by making sure every term in the first bracket meets every term in the second.

Maths (school) · Part 02: Algebra basics · Card 4 of 8 · Last updated 2026-10-19

## Analogy

Like a handshake round a table: everyone from group A shakes hands with everyone from group B.

## Example

**(x + 2)(x + 5)**

x^2 + 5x + 2x + 10
= x^2 + 7x + 10

## In practice

The area of a garden with sides (x + 2) and (x + 5) metres uses double brackets.

## Practice

### Flashcards

- **Expand (x + 2)(x + 5).** x^2 + 7x + 10.

## Questions people ask

### What does FOIL mean?

FOIL stands for First, Outer, Inner, Last. It lists the four multiplications in a double bracket. For (x + 2)(x + 5): x times x, x times 5, 2 times x, 2 times 5. A grid works too, and it always gives four terms to collect.

### Why do double brackets give four terms?

Each of the two terms in the first bracket multiplies each of the two terms in the second, so 2 x 2 = 4 products. Two of them are often like terms and combine. That is why the middle result is usually a single x term.

## Related concepts

- [Simplifying expressions](https://studyvisually.com/learn/science/maths-school/maths-school-part-2/maths-school-part-2-concept-1)
- [Substitution](https://studyvisually.com/learn/science/maths-school/maths-school-part-2/maths-school-part-2-concept-2)
- [Expanding brackets](https://studyvisually.com/learn/science/maths-school/maths-school-part-2/maths-school-part-2-concept-3)
- [Factorising](https://studyvisually.com/learn/science/maths-school/maths-school-part-2/maths-school-part-2-concept-5)

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