How do you use summation notation to expression the sum #15-3+3/5-...-3/625#?
Please see the explanation.
Let try to fill in the finite sum:
If your remove a common factor of 15, you get:
You can write 1 as
Because the minus sign appears on the odd powers, one can see that we are raising -5 to a negative power:
To obtain the original sum, multiply by 15: