Question 856145
<pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
arithmetic sequence 8, 14, 20 … : d = 6
 {{{a[n]=a[1]+(n-1)*d}}}
{{{a[22] = 8 + 21*6 = 134}}}
{{{S[n]=(n(a[1]+a[n]))/2}}}
{{{S[22] = 11(8+134) = 1562}}}