Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
0.133681 = 12x^-1+5x^-2+5x^-3+20x^-4
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random