A linear equation in two variables is of the form $ax + by + c = 0$, where

A linear equation in two variables is of the form $ax + by + c = 0$, where $a \ne 0, b \ne 0$. If the values of “$a$” and “$b$” are equal to 0, the equation becomes$c =0$. Hence, the values of $a$and $b$ should not be equal to 0.