[tex]\bf \cfrac{~~-\frac{3}{7}~~}{\frac{9}{4}}\implies -\cfrac{~~\begin{matrix} 3 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}{7}\cdot \cfrac{4}{\underset{3}{~~\begin{matrix} 9 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}}\implies -\cfrac{4}{21}[/tex]
