Answer:
[tex] t = \frac{U -C }{Cr}[/tex]
Step-by-step Explanation
[tex]U = C(1+rt) \\ \\ \frac{U}{C} = (1 + rt) \\ \\ \frac{U}{C} - 1 = rt\\ \\ \frac{U -C }{C} = rt\\ \\ \huge \red{ \boxed{ t = \frac{U -C }{Cr} }}[/tex]
