Question

find the 10th term of the arithmetic sequence that begins with 1/7 and whose common difference is 2/5

Answer 1

$u_{n}= a+(n-1)d$
$u_{10}= \frac{1}{7}+(10-1) \frac{2}{5}$  
$u_{10}=\frac{1}{7}+9* \frac{2}{5}$
$u_{10}= \frac{1}{7}+ \frac{18}{5}$
$u_{10}= \frac{5}{35}+ \frac{126}{35}= \frac{131}{35}$