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