Algebra – expand three brackets

Following a recent test for Year 10 (UK age 14-15) I wanted to use colour to show clearly a way to make sure all terms have been included when three brackets have to be expanded (new to the UK GCSE qualification). (Colour can be so useful in Mathematics – something I have written on before).

Expand Brackets Colleen Young

I have created this example using Excel. This is just a simple example with positive coefficients only; I wanted to start by being clear on making sure that all combinations are included. There are various FOIL and quick methods available if you search but my own preference is a more systematic approach. An advantage of using Excel is the ability to trace precedents (Formulas menu).
Excel trace precedents

The numbers could be changed and of course any examples could be made up and checked on WolframAlpha.
WolframAlpha brackets

I have also collated some Algebra resources (many topics) – examples and exercises on Mathematics for Students. Note the very clear workbooks from Plymouth University

Functions - Plymouth University

Functions – Plymouth University

One comment on “Algebra – expand three brackets

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