youngguru

The sum of the first n terms of a series is 1-(3/4). Obtain an expression for the nth term of the series. Prove that the series is geometric, and state the values of the first term and the common ratio. Please show workings

One sequence of alternating terms of the series 1+2+3+4+5+8+... forms an arithmetic progression, while the other sequence of alternating terms forms a geometric progression. Sum the first 10 terms of each progression and hence find the sum of the first 20...

1/(y-x), 1/(2y), 1/(y-z)

I've found the first 10 terms of each progression, but m having problems with sum of the first 20 terms of the series. Am I going to solve for A.P and G.P differently.