Question

if five times the fifth term of an ap is equal to 8 times its 8 term show that its 13th term is 0​

Answer 1

Answer:

a5=a+4d

a8=a+7d

A/Q

5(a+4d)=8(a+7d)

5a+20d=8a+56d

5a-8a=56d-20d

-3a=36d

-a=12d

d=-a/12

a13=a+12d

a13=a+12(-a/12)

a13=a+(-a)

a13=a-a

a13=0