jmc

The prime factorization of $6545$ is $5\cdot 7\cdot 11\cdot 17=385\cdot 17$, which contains a three digit number, but we want 6545 to be expressed as ab x cd. Now we do trial and error: $$5\cdot 7=35\text{, }11\cdot 17=187\text{ X}$$ $$5\cdot 11=55\text{, }7\cdot 17=119\text{ X}$$ $$5\cdot 17=85\text{, }7\cdot 11=77\surd$$ $$85+77=\boxed{162}$$