An equation of the type ax+by+c = 0 is a linear equation. It shows relation between two algebraic expressions with the sign of equality (=) An equation holds true for particular value or values of the variable/ variables. To find the value of a single variable, only one equation is needed. In order to find the values of two variables, two equations are

necessary. Accordingly, three equations are needed to find the values of three variables, and so on. There are various types of equations viz. Linear quadratic equation, Cubic equation etc.