Question 1086131
How to find the sum of the first 10 terms of each arithmetic sequence?

 1. a(sub1) = 11 and a(sub10) = 38

 2. a (sub1) = 10 and a(sub10) = 55
<pre>Use the formula for the sum of an AP: {{{S[n] = (n/2)(a[1] + a[n])}}}, where:
{{{S[n]}}} = Sum of the 1st 10 terms ({{{S[10]}}}, in this case)
{{{n}}}  = Number of terms (10, in this case)
{{{a[1]}}} = 1st term (11, in this case)
{{{a[n]}}} = Value of last term (38, in this case)