Question

Which of the following is not a linear equation in one variable ? why?
$2x-1=\frac{3}{2}$
$x+3y=5$
$a=0$

Answer 1

Consider the given equation.

$2x-1=\frac{3}{2}$

Here, only one variable is given and highest order of the variable is 1. Therefore, this is a linear equation in one variable.

Consider the given equation.

$x+3y=5$

Here, highest degree of the variables is 1, but there are two variables, $x$ and $y$. Therefore, this is not a linear equation in one variable.

Consider the given equation.

$a=0$

Here, only one variable is given and highest order of the variable is 1. Therefore, this is a linear equation in one variable.