**Important Concepts and Formulas**

1.
An
equation of the form

*ax + by + c = 0*, where a, b and c are real numbers such that a and b are not both zero, is called a linear equation in two variables.
2.
A
linear equation in two variables has infinitely many solutions.

3.
The
graph of every linear equation in two variables is a straight line.

4.
The
equation of the x-axis is

*y = 0*and the equation of the y-axis is*x =*0.
5.
The
equation of a straight line parallel to y-axis is

*x = a*.
6.
The
equation of a straight line parallel to x-axis is

*y = a*.
7.
An
equation of the type

*y = mx*represents a line passing through the origin.
8. Every point on the graph of a linear
equation in two variables is a solution of the linear equation. Moreover, every
solution of the linear equation is a point on the graph of the linear equation.

To study about the linear equations in two variables ------
Click Here!