CaLcUlAtOr BaNnEd

Notice the last digits of both the expressions. You must be familiar with patterns that we require here.

The last digits of $527^{379}$ and $473^{379}$ will be $3$ and $7$ respectively. Hence when added, the last digit of the sum will be $0$ , which means that the sum is a multiple of $10$ .

The last digits of $527^{166}$ and $473^{166}$ will be $9$ . Hence when subtracted, the last digit of the difference will be $0$ , which means that the difference is a multiple of $10$ .

Hence the answer.