[tex]\bf \cfrac{2}{5}+\cfrac{5^2-10}{5^2}\implies \cfrac{2}{5}+\cfrac{~~\begin{matrix} 5^2 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}{~~\begin{matrix} 5^2 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}-\cfrac{10}{5^2}\implies \cfrac{2}{5}+1-\cfrac{10}{25}\implies \cfrac{2}{5}+1-\cfrac{2}{5}\implies 1[/tex]
