Using ab rather than a x b

Guide

In algebra, we often use shorthand notation to make expressions more concise and easier to manipulate. One of the most common examples of this is writing 'ab' instead of 'a × b'. This notation is used to represent multiplication without using the multiplication symbol (×).

Key points:

• When we write two letters or a number and a letter next to each other without any operation symbol, it means we're multiplying them.
• This notation applies to variables (letters) and numbers.
• The order doesn't matter for multiplication, so 'ab' is the same as 'ba'.

Worked Examples

1. Express '3 × x' using the shorter notation: 3x
2. Write '5 × y × 2' using the shorter notation: 5y2 or 10y
3. Express 'a × b × c' using the shorter notation: abc
4. Write 'm × n × 4' using the shorter notation: 4mn
5. Express '2 × x × y × 3' using the shorter notation: 6xy

Practice Exercises