Question

The 6th term of an AP is -10 and its 10th term is -26. Determine the 15th term of an AP

Answer 1

a+5d=-10-(1)
a+9d=-26-(2)
and subtracting equation first from second,
4d=16
d=4
then a=-10-5d
=-10-5(4)
=-10-20
a=-30
15 term of AP is,
a+14d
=-30+14 (4)
=-30+56
=14

Answer 2

Answer:

a15= 14

Step-by-step explanation:

a6=-10

a10=-26

a6=a+5d

-10=a+5d --(1)

a10=a+9d

-26=a+9d --(2)

subtracting (2) from (1)

a+9d=-26

a+5d=-10

-------------

4d= 16

d=16/4

d=4

then a=-10-5d

=-10-5(4)

=-10-20

a =-30

15th term of ap is

a15=-30+14(4)

=-30+56

=14

hope it works ;)