Algebraic Fraction - GCSE Maths Definition

Reviewed by: Dan Finlay

Last updated

What is an algebraic fraction?

In GCSE maths, an algebraic fraction is a fraction where the numerator and/or denominator contain an algebraic expression. Here are some examples of algebraic fractions:

  • fraction numerator 2 over denominator x plus 1 end fraction

  • fraction numerator 2 x plus 3 over denominator x plus 1 end fraction

  • fraction numerator x squared minus 1 over denominator x minus 1 end fraction

Algebraic fractions follow the usual rules of numerical fractions.

To simplify algebraic fractions, cancel out common factors from the numerator and the denominator.

fraction numerator open parentheses x plus 1 close parentheses open parentheses x minus 3 close parentheses over denominator open parentheses x plus 1 close parentheses open parentheses 2 x minus 5 close parentheses end fraction equals fraction numerator x minus 3 over denominator 2 x minus 5 end fraction

To add or subtract algebraic fractions, find equivalent fractions so that both fractions have a common denominator.

2 over x plus fraction numerator x minus 2 over denominator x plus 1 end fraction equals fraction numerator 2 open parentheses x plus 1 close parentheses over denominator x open parentheses x plus 1 close parentheses end fraction plus fraction numerator x open parentheses x minus 2 close parentheses over denominator x open parentheses x plus 1 close parentheses end fraction equals fraction numerator 2 open parentheses x plus 1 close parentheses plus x open parentheses x minus 2 close parentheses over denominator x open parentheses x plus 1 close parentheses end fraction

To multiply algebraic fractions, multiply the numerators together and multiply the denominators together.

fraction numerator x over denominator x plus 1 end fraction cross times fraction numerator x minus 1 over denominator 4 end fraction equals fraction numerator x open parentheses x minus 1 close parentheses over denominator 4 open parentheses x plus 1 close parentheses end fraction

To divide algebraic fractions, multiply the first fraction by the reciprocal of the second fraction.

fraction numerator x over denominator x plus 1 end fraction divided by fraction numerator x minus 1 over denominator 4 end fraction equals fraction numerator x over denominator x plus 1 end fraction cross times fraction numerator 4 over denominator x minus 1 end fraction equals fraction numerator 4 x over denominator open parentheses x plus 1 close parentheses open parentheses x minus 1 close parentheses end fraction

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Dan Finlay

Reviewer: Dan Finlay

Expertise: Maths Subject Lead

Dan graduated from the University of Oxford with a First class degree in mathematics. As well as teaching maths for over 8 years, Dan has marked a range of exams for Edexcel, tutored students and taught A Level Accounting. Dan has a keen interest in statistics and probability and their real-life applications.

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