7 x 2 = 14

4 x 7 = 28

7 x 6 = 42

3 x 7 = 21

5 x 7 = 35

2 x 7 = 14

7 x 4 = 28

6 x 7 = 42

7 x 3 = 21

7 x 5 = 35

7 x 2 = 14

4 x 7 = 28

7 x 6 = 42

3 x 7 = 21

5 x 7 = 35

2 x 7 = 14

7 x 4 = 28

6 x 7 = 42

7 x 3 = 21

7 x 5 = 35

Học sinh nhẩm và ghi kết quả như sau:

3 x 4 = 12    2 x 6 = 12     4 x 3 = 12    5 x 6 = 30

3 x 7 = 21    2 x 8 = 16     4 x 7 = 28    5 x 4 = 20

3 x 5 = 15   2 x 4 = 8        4 x 9 = 36    5 x 7 = 35

3 x 8 = 24    2 x 9 = 18     4 x 4 = 16    5 x 9 = 45

3 x4 = 12

3 x7 = 21

3 x5 = 15

3 x8 =24

2 x 6= 12

2 x8 = 16

2 x4 =8

2 x9 =18

4 x3 =12

4 x7 =28

4 x9 =36

4 x4 =16

5 x6 =30 

5 x4 =20

5 x7 =35

5 x9 =45

3 x 4 = 12    2 x 6 = 12     4 x 3 = 12    5 x 6 = 30

3 x 7 = 21    2 x 8 = 16     4 x 7 = 28    5 x 4 = 20

3 x 5 = 15   2 x 4 = 8        4 x 9 = 36    5 x 7 = 35

3 x 8 = 24    2 x 9 = 18     4 x 4 = 16    5 x 9 = 45

1.

\(8\times8=64\)

\(6\times4=24\)

\(4\times4=16\)

2. 

Ta có:

\(4\times6=24\)              \(7\times5=35\)

Vì \(24< 35\) nên \(4\times6< 7\times5\)

Vậy...

_____

Ta có:

\(5\times7=35\)              \(8\times9=72\)

Vì \(35< 72\) nên \(5\times7< 8\times9\)

Vậy....

_____

Ta có: 

\(3\times5=15\)              \(6\times9=54\)

Vì \(15< 54\) nên \(3\times5< 6\times9\)

Vậy...

\(#Wendy.Dang\)

8 x 8 =64

6 x 4 =24

4 x 4=16

Bài 2 : < , > , = 

4 x 6  <  7 x 5

5 x 7  < 8 x 9

3 x 5 <  6 x 9 

Em cảm ơn POP POP ạ

a) 6 x 2 = 12        6 x 3 = 18        6 x 8 = 48        6 x 1 = 6

     6 x 4 = 24       6 x 5 = 30       6 x 9 = 54       1 x 6 = 6

6 x 6 = 36       6 x 7 = 42       6 x 10 = 60       0 x 6 = 0

b) 6 x 5 = 30        6 x 4 = 24        3 x 6 = 18       2 x 6 = 12

     5 x 6 =30       4 x 6 = 24       6 x 3 = 18       6 x 2 =12

\(\dfrac{4}{5}\times\dfrac{3}{7}\times\dfrac{4}{5}\times\dfrac{6}{7}\times\dfrac{4}{14}=\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{2}{7}=\dfrac{4}{5}\times\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)=\dfrac{4}{5}\)

a) 6 x 3  =18               7 x 5 =35                     9 x 4=36              8 x 10=80

b) 8 x 7 =56                3 x 9 =27                    5 x 6=30              4 x 8=32

a) 6 x 3=18                 7 x 5=35                     9 x 4=36              8 x 10=80

b) 8 x 7=56                 3 x 9=27                     5 x 6=30              4 x 8=32

`(3xx4xx7)/(5xx3xx4)=7/5`

`(2xx5xx6xx8)/(6xx2xx8xx9)=5/9`

`(4xx5xx6)/(3xx10xx8)= (4xx5xx6)/(3xx5xx2xx4xx2)= 6/(3xx2xx2)= 6/(6xx2)=1/2`

\(a,\dfrac{3\times4\times7}{5\times3\times4}=\dfrac{7}{5}\)

\(b,\dfrac{2\times5\times6\times8}{6\times2\times8\times9}=\dfrac{5}{9}\)

\(c,\dfrac{4\times5\times6}{3\times10\times8}=\dfrac{2}{4}=\dfrac{1}{2}\)

Bạn ơi không gửi linh tinh nhé

2017 nhé

a) \(\frac{18}{45}-\frac{4}{12}-\frac{6}{9}-\frac{21}{35}=\frac{2}{5}-\frac{1}{3}-\frac{2}{3}-\frac{3}{5}\)

\(=\left(\frac{2}{5}-\frac{3}{5}\right)-\left(\frac{1}{3}+\frac{2}{3}\right)\)

\(=\frac{-1}{3}-1\)

\(=\frac{-4}{3}\)

b) \(\frac{4}{3}+\frac{3}{5}+\frac{7}{3}+\frac{2}{5}+\frac{1}{3}=\left(\frac{4}{3}+\frac{7}{3}+\frac{1}{3}\right)+\left(\frac{3}{5}+\frac{2}{5}\right)\)

\(=4+1=5\)

c) \(\frac{1}{3}.\frac{4}{5}.\frac{1}{3}.\frac{6}{5}=\frac{8}{75}\)

d) \(\frac{6}{7}.\frac{8}{13}+\frac{6}{7}.\frac{9}{13}-\frac{3}{13}.\frac{6}{7}\)

\(=\frac{6}{7}.\left(\frac{8}{13}+\frac{9}{13}-\frac{3}{13}\right)\)

\(=\frac{6}{7}.\frac{14}{13}\)

\(=\frac{12}{13}\)