Finding Rational Numbers with Given Properties

Consider the following statement:

The sum of two rational numbers, $a$ and $b$, is equal to the product of those two numbers. This can be mathematically expressed as:

$$ a + b = ab $$

Given the equation above, if $a$ is represented as $\f\frac{m}{n}$ where $m$ and $n$ are integers, find the value of $a$ if $b$ is $\frac{3}{2}$.