Originally Posted by

**thekrown** 3. a) Write the series 60 -15 +15/4 -15/16 +15/64 -15/256.

My work:

I discovered each term is divided by -4.

60 / -4 = -15

15 / -4 = 15/4

15/4 / -4 = -15/16

Total terms 6 (above sigma, also n)

First term k=1 (first term)

Now for the part on the right of sigma, I have difficulty with this.

I wrote the part on the right of sigma, which should be {a+(n-1)d}, as {60+95) / -4}.

I've never encountered a series where everything is divided rather than multiplied so I'm a little lost.

Please help.