What is an example of a mathematical equation?

Any equation has to have an equal sign. For example, 5x = 30 - there is an equal sign

The most basic and common algebraic equations in math consist of one or more variables. For instance, 3x + 5 = 14 is an equation, in which 3x + 5 and 14 are two expressions separated by an 'equal' sign. In an algebraic equation, the left-hand side is equal to the right-hand side.