Linear equations in two variables are a system of equations with a unique solution, no solutions, or infinitely many solutions. A linear system of equations may have 'n' number of variables. An important thing to keep in mind while solving linear equations with n number of variables is that there must be n equations to solve and determine the value of variables. The set of solutions obtained on solving these linear equations is a straight line. Linear equations in two variables are the algebraic equations which are of the form y = mx + c, where m is the slope and c is the y-intercept. They are the equations of the first order. For example, y = 2x+3 and 2y = 4x + 9 are two-variable linear equations. The linear equations in two variables are of the highest exponent order of 1 and have one, none, or infinitely many solutions.