00:01
So for this problem, we can see that we're going to need to break apart this sum into two separate sums in order to allow us to evaluate using our formulas that we know.
00:12
So one of our properties of sums tells us that we can go ahead and break this apart at a plus or minus sign.
00:19
So that means that we can rewrite this sum as two individual sums.
00:24
They both are going to have the same boundaries as the original.
00:28
And one of our sums is going to be 2k squared.
00:31
So if we multiply this out, it's going to be 4k squared.
00:35
And then our second sum will be minus, again with the same boundaries, k is equal to 1 through 25 of 100k.
00:43
And our formulas that we know are going to allow us to evaluate this involve k squared or just a k without the coefficient.
00:52
And so in order to get rid of this coefficient, we can go ahead and use another rule of sums, and that allows us to essentially just bring the coefficient to the outside of our sum...