The vocabulary of algebra, the identity sign, finding unknowns in an identity, and simplifying algebraic fractions.
What you will learn
- Tell an expression, equation, formula and identity apart
- Use ≡ and show an identity is true
- Find unknown numbers in an identity
- Simplify algebraic fractions by cancelling (Higher)
Four words
- An expression has no equals sign: 3x + 5.
- An equation is true for particular values: 3x + 5 = 20 only when x = 5.
- A formula links quantities: A = lw.
- An identity is true for every value, written with ≡: 2(x + 3) ≡ 2x + 6.
The rest of this lesson and its 7 practice questions are locked.
In this lesson
- Four words
- Using an identity
- Algebraic fractions (Higher)
7 practice questions, marked as you go; about 20 minutes in all.
Key terms
Expression, Equation, Formula, Identity
In this unit: Algebraic expressions
The language of algebra: writing and substituting into expressions, simplifying, expanding brackets, factorising, and telling expressions, equations, formulae and identities apart.
- Writing and using algebra
- Simplifying
- Expanding brackets
- Factorising into one bracket
- Expressions, equations, formulae and identities