Question

Tính:

Answer 1

a)

50 – 10 – 30 = 10                                       

67 – 7 – 20 = 40

Answer 2

b)

2 + 4 – 3 = 3                                                

9 – 5 + 2 = 6

20 + 40 – 30 = 30                                        

90 – 50 + 20 = 60