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Algebra Toolkit
Algebra and Sequences
Terms
- A term is a single part of an expression: a number, a letter, or numbers and letters multiplied together
- 20, x, 5x, 6xy and 4x² are all terms
- A term that is a number alone is a constant, because its value never changes
- The number multiplying the letters is the coefficient
- In 8m the coefficient is 8, and in −t it is −1, since a coefficient of 1 is not written
Expressions, equations, formulas and identities
| Name | What it is |
|---|---|
| Expression | Terms combined by operations, with no equals sign and nothing to solve |
| Equation | Two expressions set equal, true only for particular values |
| Formula | A rule connecting quantities, used to calculate one from the others |
| Identity | A statement true for every value, written with ≡ |
Factors
- A factor of a term divides it exactly
- 5 and x are both factors of 5x, because 5 × x = 5x
- A common factor divides two or more terms, and the highest one is what factorising takes out
- 12ab and 18b share the factor 6b, which is the highest available