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.
solve x1+3*x2+4*x3=1, x1-x3=9, x1+x3=8
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random