What are rational expressions?

• Rational?numbers are numbers that can be written as a fraction (quotient)Rational comes from?ratio?– a number is rational if it can be written as a ratio of two integers – ie a fraction!
• A?rational?expression?is an?algebraic?fractionThe ratio between two algebraic expressions (usually polynomials)

Factor theorem

• In order to simplify a rational expression you'll need to remember the factor theorem

How to simplify a rational expression (algebraic fraction)

• Start by?factorising?polynomials using?factor?theorem?or?algebraic?division

• cancel?any common (linear) factors

• recognise?a?top-heavy (improper)?rational expression, simplify if needed