[tex]\bf \stackrel{\textit{let's recall that }}{a+a \implies a(1+1)\implies a(2)\implies 2a} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{a}{\cfrac{9}{12}}+\stackrel{a}{\cfrac{9}{12}}\implies \stackrel{a}{\cfrac{9}{12}}(1+1)\implies \cfrac{9}{12}(2)\implies 9\cdot \cfrac{2}{12}\implies 9\cdot \cfrac{1}{6}\implies \cfrac{9}{6}\implies \cfrac{3}{2}[/tex]
