C. Write the value of the expression on the blank.
1. 1-561 =
2. I+181 =
3. 1+751 =
4. I+311 =
5. 1+571 =
6. I+831 =
7. 1-3451 =
8. 1-5981 =
9. l-1121 =
10. I-1431 =