As apm says, multiply by (1+x)^2 to get:
-3000(1+x)^2 + 2500 (1+x) + 1000 = 0
To make it a bit easier, multiply by -1, then divide by 500:
6(1 + x)^2 - 5(1 + x) - 2 = 0
As apm says, now expand, then use quadratic.
You'll get 2 answers: .1287~ and -1.2953~
These will be from:
x = [-7 +- sqrt(73)] / 12 (which you'll get from the quadratic).
You can make it easier still by letting a = 1 + x; then equation becomes:
6a^2 - 5a - 2 = 0
After getting a by using the quadratic, don't forget to re-substitute:
1 + x = a
x = a - 1
