Question

Please help with this question, I need to make sure I'm right. Thanks

Answer 1

an=4n+1

Sum of first 30 terms

a1+a2+.................a30

 Sn=(a1+an)*n/2

a1-----------first terms

an=---------last term-----a30

n= number of terms-----30

 calculation of a1

a1=4n+1=4*1+1=5

 calculation of an

a30=4*30+1=121

 S30=(a1+a30)*30/2

S30=(5+121)*30/2=1890

The sum of first 30 terms is 1890