<< just trying to test the power of computers >>
Do you have access to a spreadsheet? Most OEM computers have some form of spreadsheet that comes installed. Or you can download one quickly.
Type your equation into the spreadsheet. Hit solve. Wait 0.01 seconds. Get your answer.
If that isn't the answer you wanted, give it a different initial guess. Hit solve. Wait 0.01 seconds. Get your answer.
Sure there are better methods. However, this one is easiliy available to most computer users.
Edit: the nice thing about this method it that you can easily solve for multiple variables at the same time. Many graphic calculators don't have that capability built in. Yes you can program it, but you could just as easily program your computer to do the same thing...