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.
90·x·(1+x)^12-7·(1+x)^12+7-x·105=0
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
