Question

If 12 term of an ap is minus 13 and the sum of its first 4 term is 24 what is the sum of its first 10 term's

Answer 1

t(12) = -13

a+11d = -13..........(1)

S(4) = 24

4/2(2a+3d) =24

2a+3d =12.........(2)
2a+22d = -26
___________
-19d = 38

d = -2

(1)....a-22=-13

a = 9

now S(10) = n/2(2a+(n-1)d)

= 5 (18+9(-2))

= 5 (0) = 0

Answer 2

Answer:

Refer to the attachment ✌