Question

1.42

Answer 1

a) 45.29=45(30-1)=45.30-30.1=1350-45=1305

b) 15(1000-2)=15.1000-15.2=1500-30=14970

Answer 2

Bạn nhầm bài rồi tôi cần bài 1.42

Answer 3

a) 5.11.18 + 9.31.10 + 4.29.45

= 5.11.9.2 + 9.31.5.2 + 2.2.29.9.5

= 9.5.2.(11 + 31 + 2.29)

= 90.100

= 9000

b) 37.39 + 78.14 + 13.85 + 52.55

= 37.39 + 39.2.14 + 13.17.5 + 13.4.11.5

= 39.(37 + 2.14) + 13.5.(17 + 4.11)

= 39.65 + 65.61

= 65.(39 + 61)

= 65.100

= 6500