#### Answer

$a_1=\frac{3}{5}$
$d=-\frac{1}{2}$

#### Work Step by Step

In an arithmetic sequence, the common difference can be calculated as the difference of any two subsequent terms:
$d=a_2-a_1=\frac{1}{10}-\frac{3}{5}=-\frac{5}{10}=-\frac{1}{2}$
The first term is:
$a_1=\frac{3}{5}$.