## How to work with Algebra: Part 3

Have you ever wondered why we use the letter X in algebra so much? We also use the letter X for phrases like  “X marks the spot”. In fact we use X whenever we want to  represent something unknown. It is believed that this originates from the mathematician René Descartes. In his book , The Geometry,  he used the last three letters of the alphabet to represent unknown quantities. We do the same when we solve equations to find out what x is. He chose a, b, and c to stand for known quantities.

If you need more help with algebra check out Part 3 of our “How to” Algebra guides. This section provides guidance on factorising expressions, including single brackets and the difference of two squares. There are example questions for you to try at the end of the powerpoint, and answers are included so you can check your understanding.

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Come back and check our blog page for more resources to help you improve your understanding of different topics in various subjects.  Part 4 of our “How to work with Algebra” guide will be out next week, with support on factorising quadratic expressions.