Question 1175457
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Hi
 {{{a[n]=a[1]+(n-1)*d}}}
{{{a[6]=a[1]+(5)*d}}} = 0  
{{{a[10]=a[1]+(9)*d}}} = 16 
   a + 9d = 16 
   <u>a + 5d = 0</u>    |Subtract 2nd from 1st
       4d = 16
        d = 4   and a1 = -20    {{{ a[1] = -5d}}}
   
{{{S[n]=(n(a[1]+a[n]))/2}}}   {{{a[14]=-20 +(13)*4}}}  
{{{S[14]=(14(-20 + 32))/2 = 84}}}
Wish You the Best in your Studies.
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