A linear equation in one variable is an equation that have the same solution as the equation of the form ax + b = 0, where a and b are integers and a is not equal to zero.
In other words, if an equation can be written in the form ax + b = 0, then it is a linear equation in 1 variable.
In ax + b = 0, a is a coefficient, b is a constant, and x is a variable
For example, 5x + 2 = 3x + 6 is a linear equation in one variable since it is possible to write it in the form ax + b = 0 using some of the properties of equality.
5x + 2 = 3x - 4
5x + 2 + 4 = 3x - 4 + 4 (addition property of equality)
5x + 6 = 3x
5x - 3x + 6 = 3x - 3x (subtraction property of equality)
2x + 6 = 0
Since 5x + 2 = 3x + 6 can be written as 2x + 6 = 0, it is a linear equation
6x + 2 = 20
4x - 5 = 12 + - 5
2x - 8 + 6 = 7
-x + 5 = 4x
100 + 100x = 200 + 300