\(\frac{\textcolor{red}{-9}}{\textcolor{blue}{10}}*\frac{\textcolor{red}{2}}{\textcolor{blue}{3}}=\frac{\textcolor{red}{-18}}{\textcolor{blue}{30}}\)
Notice how the numerators were multiplied together to get the result of the numerator, and the denominators were multiplied together to get the result of the denominator. Now, we must simplify the fraction to its simplest terms. In this case, -18 and 30 share a greatest common factor of 6.
\(\frac{-18}{30}\div\frac{6}{6}=\frac{-3}{5}\)
There you go!