Question

Find the sum of the following series upto n terms: 5^2+6^2+7^2+...20^2

Answer 1

Answer:

Step-by-step explanation:

Let's try it

5²+6²+7²...20²

(5+6+7+8...+20)²

an=a+(n-1)d

20=5+(n-1)(1)

n=16

=Here a=5,l=20 and n=16

hence Sn=n/2(a+l)

=200

=(200)²=40000

Hope it helps!!

Answer 2

Answer:

hey mate here is ur answer

Step-by-step explanation:

hope

it

is

enough