I complete forgot the formula to solve this sort of equations ... can someone please put me on the right track.

Key:

- Saving rate = Q
- Annual salary=W
- Rate of salary increases per year (in percentage) = Z
- Initial year = A
- Maximum number of years = N
- Total savings per year= Gx
- Total savings: H

- Formula: G=W*[Power(1+Z),(N-A)]*Q

If A=1 W=40000 Q=.3 Z=.02

Then in the first year N= 1 thus G0= 12000

Then in the second year N=2 thus G1= 12240

Total savings from first year to second year: H= G0+G1

Problem: Derive the formula to determine the total savings from the first year to the "N" year? [where N is a natural positive whole number]

Correct me if I'm wrong:

- This is what it must look like:

H=G0+G1+G2+G3+........GN

= W*Q*( 1+ [Power(1+Z),2] +[Power(1+Z),3]+.....+ [Power(1+Z),(N-A)])

But how do we reduce this to a single formula.