6. 90:30 100:20 7·8 – 42:7 9·9 – 9·3 36:4+27 50–21:3

1. $$90:30 = 3$$.
2. $$100:20 = 5$$.
3. $$7\cdot8 - 42:7 = 56 - 6 = 50$$.
4. $$9\cdot9 - 9\cdot3 = 81 - 27 = 54$$.
5. $$36:4 + 27 = 9 + 27 = 36$$.
6. $$50 - 21:3 = 50 - 7 = 43$$.

Ответ: 3; 5; 50; 54; 36; 43.