Consider points O, A, B, C, D and R in the diagram below, such that AR = 4, BR = 2, CR = 2, and DR = 6:
If there exist real numbers and such that
\((1-t) \overrightarrow{OA} + t \overrightarrow{OB} = (1-u) \overrightarrow{OC} + u \overrightarrow{OD}\)
find t and u.
