Question 1196256
<br>
A note to help you with your studies of mathematics....<br>
Technically, the question can't be answered; we can't solve for "U", because "U" does not appear in the given equation.<br>
It is not at all uncommon to have two different variables like r and R in the same problem.  So in a problem involving both "u" and "U", it must be assumed that those represent different numbers, unless that statement of the problem specifically says they are the same.<br>