Some examples of linear equations are : 2x + 3y = 4, x + 2
= 0, 5x + 2y - 3z = 1
In a linear equation the degree of symbols such as x, y and
z is 1.
containing terms involving degrees other than 1, for example
x2 , y3 , 1 / x are non-linear.
The graph of an equation such as 2x + 3y = 4 is a straight
line. For this reason it is said to be a linear equation.