Question

the 14 term of an AP is twice at 9 term . if it's 6 term is -8 then find its sum of its 20 term​

Answer 1

Answer:

0

Step-by-step explanation:

T12=a +11d

-13=a+11d

a=-13-11d                            --(i)

S4=2(2(a)+3d)

24=2(2(-13-11d)+3d)

On simplification,

d=-2

and a=9

now, S10=5[2(9)+9(-2)]

Therefore

S10=0