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.
0.7201/99.275=2^(-t/7.04e8)/2^(-t/4.46e9) solve for t
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random