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Algebraic fractions - EduqasSimplifying rational expressions with factorising

Algebraic expressions in fraction form are rational. Methods of adding, subtracting, multiplying and dividing fractions plus expanding and factorising can be used to simplify rational expressions.

Part of MathsAlgebra

Simplifying rational expressions with factorising

Some expressions do not have obvious common . In these cases, it is necessary to factorise either the or the , or both, to find common factors.

Example

Simplify \(\frac{3t + 6}{3t}\).

The numerator of this fraction will factorise as there is a common factor of 3.

This gives \(\frac{3(t + 2)}{3t}\). Now, there is clearly a common factor of 3 between the numerator and denominator. Cancelling this through the fraction gives \(\frac{t + 2}{t}\). There are no more common factors in this expression. Note \(t\) cannot be cancelled as there is no \(t\) term in the +2 in the numerator.

Question

Simplify \(\frac{x^2 + 5x + 4}{4x + 16}\).