Question

find the sum of first 19 terms of the AP 2 ,7 ,12 ,17​

Answer 1

Answer:

Sn=(n/2)*[2a+(n-1)d]

Sn=(19/2)*[2*2+(19-1)5)

Sn=(19/2)*[4+90]

Sn=(19/2)*[94]

Sn=(19*94)/2

Sn=893

Answer 2

Answer:

here is ur answer. .........