How to Solve simultaneous equations with Method of Substitution, Method of Elimination, Method of Comparison

## Problems Leading to Simple Equations

The chief difficulty in solving an algebraic problem lies in expressing correctly the condition of the problem by means of symbols.

## Simple Equations in One Variable

When one expression is equal to another, the equality of these expressions may hold either for all values of the unknown variables involved or for some particular values of the variables involved. In the former case it is called an identity and in latter case it is called an equation.