Question

find sum 20^2+21^2+22^2...55^2​

Answer 1

Answer:

54110

Step-by-step explanation:

at first we'll find summ of number between 1 to 55

using formuls n (n + 1)(2n + 1)/6

similarly

we'll find sum of numbers 1 to 20

at end we'll subtract thise terms.

i hope the above solution will help you.