Question

Hey so i got the correct answer to my question but I need to know how to solve it because I simply used an online calculator. It the summation of upper limit 7 and lower limit k=3 and then k^2

Answer 1

So it basically looks like this...\[\sum_{k=3}^{7}k^2\]

Answer 2

We can expand the sum as follows:
\[\sum_{k=3}^{7}k^2=3^2+4^2+5^2+6^2+7^2\]

Answer 3

I figured out how to solve it but if you know the formula that would be great because I did it the long way