1. \(37 - (12 - 9) = 37 - 3 = 34\)
2. \(48 + 12 : 6 = 48 + 2 = 50\) (не \(60 : 6 = 10\))
3. \(6 · 4 + 6 = 24 + 6 = 30\)
4. \(5 · 7 + 3 = 35 + 3 = 38\) (не \(5 · 10 = 50\))