Question

the sum of 1 - 6 terms of an ap is 0 and fourth term is 2 .find the sum of first 30 terms​

Answer 1

Step-by-step explanation:

sum of ap

a6=3(2a+5d)

0=2a+5d

a=-5d/2...1

a4=2

a+3d=2

a=2-3d...2

from 1 and 2

2-3d=-5d/2

4-6d=-5d

d=4 put this value in 2

a=2-12=-10

sum of 30 term

a30=15(-20+116)

a30=15×96=1440