Fractional equations are those equations in which the unknown or variable is in the denominator of the fraction.
To solve this type of equation, you must apply operations with algebraic fractions and pass the variable to the numerator and clearing it to find its value.
As you can see in the following equation, the variable "x" is in the denominator, so you can identify it as a fractional equation:
(1/3x+1)=2x/(x-1)