[tex] \frac{a}{7}= \frac{5}{3} } =\ \textgreater \ a= \frac{7*5}{3} =\ \textgreater \ a= \frac{35}{3} \\ \frac{a+7}{7} = \frac{ \frac{35}{3} +7}{7} = \frac{ \frac{35+21}{3} }{7} = \frac{ \frac{56}{3} }{7} =\ \textgreater \ \frac{56}{3} : 7 \\ = \frac{56}{3} * \frac{1}{7} = \frac{8}{3} [/tex]