Question

the sixth term of an AP is -10 and 10th term is -26 determine the 15th term of an AP

Answer 1

6 th term of a.p = a +5d=-10 .......(i)
10th term= a+ 9d=-26 .......(ii)
on subtracting ii from i......
we get d=-4
putting d in eq.i we get,
a=10.
hence,
15th term=
$a + (n - 1)d \\ 10 + (15 - 1) (- 4) \\ 10 - 48 = - 38$

Answer 2

I hope it will help you