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.
5*x_1+11*x_2-7*x_4=1
5*x_1+11*x_2-7*x_4=1
Natural Language
Math Input
Extended Keyboard
