How many solutions does a linear equation in one variable have?

Let’s understand this by an example:
Suppose we want to find the solution for$9x-3 = 0$
$9x-3 = 0$
$9x = 3$
Therefore$x = 1/3$
We can see that this linear equation has only one solution. i.e. $x = 1/3$
It means that there is only one number which satisfies the given equation.