Algebraic fractions
Factorise the top and the bottom of an algebraic fraction and cancel whole factors. Find the values x cannot take, then add, subtract and divide algebraic fractions over a common denominator.
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Guide
This studio follows GCSE A4 (Higher): simplifying algebraic fractions and adding, subtracting, multiplying and dividing them.
An algebraic fraction such as x2 − 9x + 3 is a fraction with letters. Like 68 = 34, you simplify it by dividing the top and the bottom by the same factor.
Only a whole factor (of an expression) cancels, never one term of a sum: in x + 33 the 3 is part of x + 3, so nothing cancels. First factorise, then cancel.
A fraction has no value when its denominator is 0. So before simplifying, find the values x cannot take.
On the board, each chip is a factor. Tap a chip, then Split to factorise it. Tap a chip above the bar, then an equal chip below it, to cancel them. To add or subtract, tap a chip of one fraction, then a × button: it multiplies that fraction's top and bottom.
Type your answer on the keypad. The fraction key puts what follows under a bar; use brackets for a bracket factor: (x − 3).