Answer :
[tex]u_{n}= a+(n-1)d[/tex]
[tex] u_{10}= \frac{1}{7}+(10-1) \frac{2}{5} [/tex]
[tex]u_{10}=\frac{1}{7}+9* \frac{2}{5} [/tex]
[tex] u_{10}= \frac{1}{7}+ \frac{18}{5} [/tex]
[tex] u_{10}= \frac{5}{35}+ \frac{126}{35}= \frac{131}{35} [/tex]
[tex] u_{10}= \frac{1}{7}+(10-1) \frac{2}{5} [/tex]
[tex]u_{10}=\frac{1}{7}+9* \frac{2}{5} [/tex]
[tex] u_{10}= \frac{1}{7}+ \frac{18}{5} [/tex]
[tex] u_{10}= \frac{5}{35}+ \frac{126}{35}= \frac{131}{35} [/tex]