Question

The sum of the series 9,5, 1,... to 100 terms is
(a) -18.900
The arithmetic means between 6 and 14 IS
(c) 19,900
(b) 18,900​

Answer 1

Answer:

-18900

Step-by-step explanation:

this series in AP

a=9 ;d=-4;n=100

so S=100/2(2×9+{100-1}-4)

=50×(18+99×-4)

=50×(18-396)

=50×-378

=-18900

i hope it's help you