Answer:
1. 123
2. 0
3. 100
Step-by-step explanation:
3s - 11 + t + 7s + 9 → 3 × 13 - 11 + -5 + 7 × 13 + 9 = 123
2s - 6r - 5s + 19r - 8s → 2 × 13 - 6 × 11 - 5 × 13 + 19 × 11 - 8 × 13 = 0
14 ( 5 + s) - 13s + 17 → 14 ( 5 + 13) - 13 × 13 + 17 = 100
I hope this helps you :D