[tex]\\ \sf\longmapsto 4\left(\dfrac{7}{8}\right)+7\left(\dfrac{3}{4}+\dfrac{1}{8}\right)-10[/tex]
[tex]\\ \sf\longmapsto \dfrac{4(7)}{8}+7\left(\dfrac{6+1}{8}\right)-10[/tex]
[tex]\\ \sf\longmapsto \dfrac{28}{8}+7\times \dfrac{7}{8}-10[/tex]
[tex]\\ \sf\longmapsto \dfrac{28}{8}+\dfrac{49}{8}-10[/tex]
[tex]\\ \sf\longmapsto \dfrac{28+49-80}{8}[/tex]
[tex]\\ \sf\longmapsto \dfrac{78-80}{8}[/tex]
[tex]\\ \sf\longmapsto \dfrac{-2}{80}[/tex]
[tex]\\ \sf\longmapsto \dfrac{-1}{40}[/tex]
