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.
3r - 1 = 39 - (r^2 - 1), 3r = 39 - r^2
3r - 1 = 39 - (r^2 - 1), 3r = 39 - r^2
Natural Language
Math Input
Extended Keyboard
