Question

[Thầy Đức Anh]

(1,5 điểm) Tính bằng cách hợp lí (nếu có thể):

a) $A=2,34+5,35+7,66+4,65$

b) $B=2,13.75+2,13.25$

c) $C=\dfrac{1}{3}-\dfrac{1}{3}: \dfrac{3}{4}$

Answer 1

[Quách Thu Thảo]

a, A = (2,34 + 7,66) + (5,35 + 4,65)

A = 10 + 10

A = 20

b, B = 2,13 . (75 + 25)

B = 2,13 . 100

B = 213

c, C = 2/3 - 4/9

C = 2/9

Answer 2

[Nguyễn An Ninh]

A=\((\)2,34+7,66\()\)+\((\)5,35+4,65\()\)

A=10+10

A=20

B=2,13*\((\)75+65\()\)

B=2,13*140

B=298,2

C=\(\dfrac{2}{3}\)-\(\dfrac{4}{9}\)

C=\(\dfrac{2}{9}\)