Add and subtract improper fractions with negatives

Give the answer as a fraction in lowest terms, or a whole number.

1. Evaluate: 1/2 + 2/3 (Write a fraction in lowest terms, or a whole number.)
2. Evaluate: 4/3 + (−1/5) (Write a fraction in lowest terms, or a whole number.)
3. Evaluate: 2/3 − (−9/5) (Write a fraction in lowest terms, or a whole number.)
4. Evaluate: 9/10 − (−2) (Write a fraction in lowest terms, or a whole number.)
5. Evaluate: 3/2 − (−1/3) (Write a fraction in lowest terms, or a whole number.)
6. Evaluate: 2 + 1/6 (Write a fraction in lowest terms, or a whole number.)
7. Evaluate: 1 + 2 (Write a fraction in lowest terms, or a whole number.)
8. Evaluate: 15/8 − (−2) (Write a fraction in lowest terms, or a whole number.)
9. Evaluate: −1/2 + 2/5 (Write a fraction in lowest terms, or a whole number.)
10. Evaluate: 1/3 − 1 (Write a fraction in lowest terms, or a whole number.)
11. Evaluate: −3/2 − 1/2 (Write a fraction in lowest terms, or a whole number.)
12. Evaluate: 1 − (−11/7) (Write a fraction in lowest terms, or a whole number.)
13. Evaluate: −3/7 − 4/3 (Write a fraction in lowest terms, or a whole number.)
14. Evaluate: 2 − 1/12 (Write a fraction in lowest terms, or a whole number.)
15. Evaluate: −1 + (−2/3) (Write a fraction in lowest terms, or a whole number.)
16. Evaluate: 7/6 − 2/3 (Write a fraction in lowest terms, or a whole number.)
17. Evaluate: −5/3 − 1/2 (Write a fraction in lowest terms, or a whole number.)
18. Evaluate: 1 − 1 (Write a fraction in lowest terms, or a whole number.)
19. Evaluate: 6/5 + (−2/3) (Write a fraction in lowest terms, or a whole number.)
20. Evaluate: −17/9 + 5/12 (Write a fraction in lowest terms, or a whole number.)