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.
(20/2 - A/2) * 3 * A = (20/2 - B/2) * 4 * B
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random