LINEAR EQUATIONS IN TWO VARIABLES Class 9

 LINEAR EQUATIONS IN TWO VARIABLES 

👉 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.

Examples:

`1.2s + 3t = 5, p + 4q = 7, πu + 5v = 9`  and  `3 = \sqrt2 x – 7y`.

Note that you can put these equations in the form `1.2s + 3t – 5 = 0, p + 4q – 7 = 0, πu + 5v – 9 = 0`  and  `2 x – 7y – 3 = 0`, respectively.

👉 Equations of the type `ax + b = 0` are also examples of linear equations in two variables because they can be expressed as

`ax + 0.y + b = 0`

For example, `4 – 3x = 0` can be written as `–3x + 0.y + 4 = 0`.