I note that your more recent post shows slightly more willing to discuss your own thoughts about the problem. That's good, because it will make it easier to help you.
I'll assume you've worked out the present momentary resistance R. (?) Using the given formula.
Then you can substitute values into 5 of the six balloons on the bottom row here...
... as explained here, but a key also in this spoiler...
Then solve for .
Next apply the product rule to V = IR...
To sub into this you need to know, which perhaps you do, whether 10-2 means that or 10.2 or whatever.
I hope that helps.
Don't integrate - balloontegrate!
Balloon Calculus; standard integrals, derivatives and methods
Balloon Calculus Drawing with LaTeX and Asymptote!