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 triangle. ...

The subject of a formula is the variable that is being worked out. It can be recognised as the letter on its own on one side of the equals sign. For example, in the formula for the area of a rectangle ...

Both algebraic and arithmetic geometry are concerned with the study of solution sets of systems of polynomial equations. Algebraic geometry deals primarily with solutions lying in an algebraically ...