b + g·(n - 1)·(0.685 + 0.0175·n) = b + g·(7/400·(n^2 - 1) + 267/400·(n - 1))

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.