4 + 5 = 9     6 + 3 = 9     1 + 8 = 9

4 + 1 + 4 = 9     6 + 1 + 2 = 9     1 + 2 + 6 = 9

4 + 2 + 3 = 9     6 + 3 + 0 = 9     1 + 5 + 3 = 9

4+5 =9 .                                                  6+3=9                                                             1+8=9                         4+1+4=9                                     6+1+2=10                                             1+2+6=9                                                          4+2+3=9                     6+3+0=9                                      1+5+3=9                                                                                                                                                                                                               Đúng thì cho chứ đừng cho sai nha

#)Giải :

\(A=\frac{1}{2}-\frac{2}{3}+\frac{3}{4}-\frac{4}{5}+\frac{5}{6}-\frac{6}{7}-\frac{5}{6}+\frac{4}{5}-\frac{3}{4}+\frac{2}{3}-\frac{1}{2}\)

\(A=\left(\frac{1}{2}-\frac{1}{2}\right)+\left(-\frac{2}{3}+\frac{2}{3}\right)+\left(\frac{3}{4}-\frac{3}{4}\right)+\left(-\frac{4}{5}+\frac{4}{5}\right)+\left(\frac{5}{6}-\frac{5}{6}\right)-\frac{6}{7}\)

\(A=0+0+0+0+0-\frac{6}{7}\)

\(A=-\frac{6}{7}\)

Bài 1:

a, 3\(\dfrac{2}{5}\) - \(\dfrac{1}{2}\) 

= \(\dfrac{17}{5}\) - \(\dfrac{1}{2}\) 

= \(\dfrac{34}{10}\) - \(\dfrac{5}{10}\)

= \(\dfrac{29}{10}\)

b, \(\dfrac{4}{5}\) + \(\dfrac{1}{5}\) x \(\dfrac{3}{4}\)

= \(\dfrac{4\times4}{5\times4}\) + \(\dfrac{1\times3}{5\times4}\)

= \(\dfrac{16}{20}\) + \(\dfrac{3}{20}\)

= \(\dfrac{19}{20}\)

c, 4\(\dfrac{4}{9}\) : 2\(\dfrac{2}{3}\) + 3\(\dfrac{1}{6}\)

= \(\dfrac{40}{9}\) : \(\dfrac{8}{3}\) + \(\dfrac{19}{6}\)

= \(\dfrac{5}{3}\) + \(\dfrac{19}{6}\)

= \(\dfrac{10}{6}\) + \(\dfrac{19}{6}\)

= \(\dfrac{29}{6}\)

Bài 2:

   3\(\dfrac{2}{5}\) + 2\(\dfrac{1}{5}\) 

= \(\dfrac{17}{5}\) + \(\dfrac{11}{5}\)

= \(\dfrac{28}{5}\)

b, 7\(\dfrac{1}{6}\) : 5\(\dfrac{2}{3}\)

= \(\dfrac{43}{6}\) : \(\dfrac{17}{3}\)

= \(\dfrac{43}{34}\)

Bài 3:

a, 800 kg 5g > 8,005 kg

b, 9 ha 4 dam² < 9\(\dfrac{5}{100}\) ha

c, 5m 5mm > 5,0005 m

d, 250 kg > \(\dfrac{1}{5}\) tấn

5 +1 = 6     4 + 2 = 6     3 + 3 = 6

6 - 5 = 1     6 - 2 = 4     6 - 3 = 3

6 - 1 = 5     6 - 4 = 2     6 - 6 = 0

5 +1 = 6    4 + 2 = 6    3 + 3 =6

6 - 5 =1     6 - 2 =4     6 - 3 =2

6 - 1 = 5    6 - 4 = 2    6 - 6 =0

Kho..................wa.....................troi.....................thi......................lanh.................ret.......................ai........................tich..........................ung.....................ho........................minh.....................cho....................do....................lanh

\(7832\)

Kho..................wa.....................troi.....................thi......................lanh.................ret.......................ai........................tich..........................ung.....................ho........................minh.....................cho....................do....................lanh

bạn viết cái này nó dễ hơn đó 

Lời giải chi tiết:

6 + 1 = 7     5 + 2 = 7     4 + 3 = 7

1 + 6 = 7     2 + 5 = 7     3 + 4 = 7

7 - 6 = 1     7 - 5 = 2     7 - 4 = 3

7 - 1 = 6     7 - 2 = 5     7 - 3 = 4

6+1=7

1+6=7

7-6=1

7-1=6

5+2=7

2+5=7

7-5=2

7-2=5

4+3=7

3+4=7

7-4=3

7-3=4

Lời giải chi tiết:

Lời giải chi tiết: