Sometimes in mathematics we like to use letters to represent numbers. The ‘value’ of these letters can change according to certain rules or conditions we are given – hence we can call them variables.

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Marguerita is a Certified Financial Planner (CFP), Chartered Retirement Planning Counselor ...

To help draw a straight line graph from its equation, fill in a table of 𝑥 and 𝑦 values. Plot the pairs of values as coordinates and join to make a line. Make sure you are confident with ...