Find the interval of convergence of the series.
\sum_(n=1)^(\infty ) ((7x)^(n))/(10^(n))\infty for infinity,
\cup for combining intervals, and appropriate type of parenthesis " (",")", "[" or "] " depending on whether the interval is open
or closed. Enter DNE if interval is empty.\sum_(n=1)^(\infty ) ((7x)^(n))/(n*10^(n))(*,*). Use symbol \infty for infinity,
\cup for combining intervals, and appropriate type of parenthesis " (",")", "[" or "] " depending on whether the interval is open
or closed. Enter DNE if interval is empty.