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.
expand (a+b-c-d)(a+b+c+d)
expand (a+b-c-d)(a+b+c+d)
Natural Language
Math Input
Extended Keyboard
