90:9•1 80:8•0 (84-77):1 (9-9):8

Interpreting colon as division and • as multiplication:

• 90:9•1 = (90 ÷ 9) × 1 = 10 × 1 = 10
• 80:8•0 = (80 ÷ 8) × 0 = 10 × 0 = 0
• (84-77):1 = (7) ÷ 1 = 7
• (9-9):8 = (0) ÷ 8 = 0

Final results: 10, 0, 7, 0.