Asked by Anonymous

if 6 times the sixth term is equal to 15 times the fifteenth term ,find its 21st term
Answered by Steve
6(a+5d) = 15(a+14d)
6a + 30d = 15a + 210d
9a = -180d
a = -20d

a + 20d = -20d + 20d = 0
Answered by Jethro
24
Answered by Lakshmi
Very bad answers 😕 not satisfied
Answered by Priya
Yes. I agree with lakshmi