Answer
Undefined or no solution when $a=3$ and one solution for all real number excluding $a=3$.
Work Step by Step
Given: $\frac{x}{3-a}=\frac{x}{3-a}$
The given equation becomes true when $x=3$ but when we put $a=3$, so
$\frac{3}{3-3}=\frac{3}{3-3} \implies \frac{3}{0}=\frac{3}{0}$; undefined solution.
Hence, we get undefined or no solution when $a=3$
and one solution for all real number excluding $a=3$.
