2 " alt=" \frac{40}{n+1}>2 " align="absmiddle" class="latex-formula">
0 " alt=" \frac{40}{n+1}-2>0 " align="absmiddle" class="latex-formula">
0 " alt=" \frac{40-2(n+1)}{n+1}>0 " align="absmiddle" class="latex-formula">
0" alt=" \frac{38-2n}{n+1} >0" align="absmiddle" class="latex-formula">
0" alt="38-2n>0" align="absmiddle" class="latex-formula">
значит 18 членов