2. 240:3+7*2 240:(3+7)*2 640:8-4*5 640:(8-4)*5 0*28:4 1*28:4

2. Вычислим:
* \(240 : 3 + 7 \cdot 2 = 80 + 14 = 94\)
* (240 : (3 + 7) \(\cdot\) 2 = 240 : 10 \(\cdot\) 2 = 24 \(\cdot\) 2 = 48)
* \(640 : 8 - 4 \cdot 5 = 80 - 20 = 60\)
* (640 : (8 - 4) \(\cdot\) 5 = 640 : 4 \(\cdot\) 5 = 160 \(\cdot\) 5 = 800)
* \(0 \cdot 28 : 4 = 0 : 4 = 0\)
* \(1 \cdot 28 : 4 = 28 : 4 = 7\)