What is 3 times negative 3 over 7

$${\mathtt{3}}{\mathtt{\,\times\,}}{\mathtt{\,-\,}}\left({\frac{{\mathtt{3}}}{{\mathtt{7}}}}\right) = {\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{7}}}}$$

Very simple. Multiply 3 by -3 in the numerator to get -9. this works for any multiplication with fractions