9 x 5 = 45

63 : 7 = 9

8 x 8 = 64

5 x 7 = 35

8 x 7 =56

3 x 8 = 24

40 : 5 = 8

5 x 5 = 25

7 x 5 = 35

7 x 8 =56

6 x 4 = 24

45 : 9 = 5

7 x 7 = 49

35 : 5 = 7

56 : 8 = 7

2 x 8 = 16

81 : 9 = 9

9 x 9 = 81

35 : 7 = 5

56 : 7 = 8

ay bạn ơi dễ vậy mà

a) = 3.50793650794

b) = 7.35238095238

tui lười viết lắm nên tui chỉ tính ra kết quả thui

a) = 1.1204
b) = 0.5714

a) = 1.1204
b) = 0.5714

a) = 1.1204
b) = 0.5714

a) \(\dfrac{5}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{5}{7}\)

\(=\dfrac{5}{7}\times\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\)

\(=\dfrac{5}{7}\times1\)

\(=\dfrac{5}{7}\)

b) \(\dfrac{1}{10}+\dfrac{5}{9}+\dfrac{4}{9}+\dfrac{9}{10}-1\)

\(=\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\left(\dfrac{1}{10}+\dfrac{9}{10}-1\right)\)

\(=1+0\)

\(=1\)

c) \(\dfrac{5}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{5}{7}+\dfrac{2}{7}\)

\(=\dfrac{5}{7}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{2}{7}\)

\(=\dfrac{5}{7}+\dfrac{2}{7}\)

\(=1\)

d) \(\dfrac{2}{7}+\dfrac{2}{8}+\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{4}{7}\)

\(=\left(\dfrac{2}{8}+\dfrac{1}{4}\right)+\left(\dfrac{2}{7}+\dfrac{1}{7}+\dfrac{4}{7}\right)\)

\(=\left(\dfrac{1}{4}+\dfrac{1}{4}\right)+1\)

\(=\dfrac{1}{2}+1\)

\(=\dfrac{3}{2}\)

e) \(\dfrac{4}{5}+\dfrac{3}{10}+\dfrac{2}{10}+0,7\)

\(=\dfrac{4}{5}+\dfrac{5}{10}+\dfrac{7}{10}\)

\(=\dfrac{4}{5}+\dfrac{12}{10}\)

\(=\dfrac{4}{5}+\dfrac{6}{5}\)

\(=\dfrac{10}{5}\)

\(=2\)

g) \(362\times728+326\times272\)

\(=326\times\left(728+272\right)\)

\(=326\times1000\)

\(=326000\) 

`!`

\(a,\dfrac{8}{9}\times\dfrac{7}{5}-\dfrac{7}{9}\times\dfrac{2}{5}+\dfrac{2}{9}\\ =\dfrac{8}{9}\times\left(\dfrac{7}{5}-\dfrac{2}{5}\right)+\dfrac{2}{9}\\ =\dfrac{8}{9}\times\dfrac{5}{5}+\dfrac{2}{9}\\ =\dfrac{8}{9}+\dfrac{2}{9}\\ =\dfrac{10}{9}\)

\(b,\dfrac{5}{9}\times\dfrac{1}{4}+\dfrac{4}{9}\times\dfrac{3}{12}\\ =\dfrac{5}{9}\times\dfrac{1}{4}+\dfrac{4}{9}\times\dfrac{1}{4}\\ =\dfrac{1}{4}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)\\ =\dfrac{1}{4}\times\dfrac{9}{9}\\ =\dfrac{1}{4}\)

Tính:

5 x 6 =30

63 : 9 =7

7 x 4 =28

45 : 5 =5

6 x 7 =42

32 : 8 =4

8 x 9 =72

35 : 7 =5

5 x 6 = 30

63 : 9 = 07

7 x 4 = 28

5 x 6 = 30
63 : 9 = 7
7 x 4 = 28
45 : 5 = 9
6 x 7 = 42
32 : 8 = 4
8 x 9 = 72
35 : 7 = 5

Bài 2:

a: 2/6x5/3=10/18=5/9

b: 11/9x5/10=55/90=11/18

c: 3/9x6/8=1/3x3/4=1/4

d: 4/9x12/16=48/144=1/3

e: 25/15x6/7=5/3x6/7=30/21=10/7

f: 6/10x15/20=90/200=9/20

Bài 1

4/5 x 6/7= 24/35

2/9 x 1/2= 2/18= 1/9

1/2 x 8/3= 8/6= 4/3

7/9 x 6/5= 42/45= 14/15

8/7 x 5/9= 40/63

10/11 x 22/15= 220/165= 4/3

Bài 2

2/6 x 5/3= 1/3 x 5/3=5/9

11/9 x 5/10= 11/9 x 1/2= 11/18

3/9 x 6/8= 1/3 x 3/4 =3/12= 1/4

4/9 x 12/16= 4/9 x 3/4= 12/36= 1/3

25/15 x 6/7= 5/3 x 6/7= 30/21= 10/7

6/10 x 15/20= 3/5 x 3/4= 9/20

bài 1

4/5 x 6/7 = 24/35

2/9 x 1/2 = 1/9

1/2 x 8/3 = 4/3

7/9 x 6/5 = 14/15

8/7 x 5/9 = 14/15

8/7 x 5/9 = 40/63

10/11 x 22/15 = 4/3

9 x 6 = 54        9 x 7 = 63        9 x 5 = 45        9 x 8 = 72

54 : 9 = 6        63 : 9 = 7        45 : 9 = 5        72 : 9 = 8

54 : 6 = 9        63 : 7 = 9        45 : 5 = 9        72 : 8 = 9

9 x 6 = 54          9 x 7 = 63          9 x 5 = 45          9 x 8 = 72

54 : 9 = 6           63 : 9 = 7           45 : 9 = 5          72 : 9 = 8

54 : 6 = 9           63 : 7 = 9           45 : 5 =9           72 : 8 =9

9 x 5 = 45

9 x 6 = 54

9 x 7 = 63

9 x 8 = 72

45 : 9 = 5

54 : 9 = 6

63 : 9 = 7

72 : 9 = 8

45 : 5 = 9

54 : 6 = 9

63 : 7 = 9

72 : 8 = 9

6 x 7 = 42

6 x 5 = 30

7 x 8 = 56 

7 x 7 = 49

7 x 9 = 63

6 x 9 = 54

42, 30, 56.