A formula is a mathematical rule or relationship that uses letters to represent amounts which can be changed – these are called variables. For example, the formula to work out the area of a ...

Before reading this guide, it may be helpful to read the guide from Module 3 (M3) on solving equations using fractions and the guide from Module 6 (M6) on changing the subject of the formula.

The quadratic formula, discovered independently by many ancient scholars ... concluding with a proof of the fundamental theorem of algebra. The book is designed for self-study, with exercises and ...

Fertility specialists have found a way for women to have babies without men. It involves a cocktail of chemicals acting as an 'artificial sperm' to trick a human egg into forming an embryo.