5/6 + 9/12 : 18/5 = 5/6 + 3/4 : 18/5

                          = 5/6 + 3/4 x 5/18

                         = 5/6 + 15/72

                         = 5/6 + 5/24

                         = 20/24 + 5/24

                         = 25/24

5/7 + 9/8 - 15/28 = 40/56 + 63/56 - 30/56

                          = 103/56 - 30/56

                          = 73/56

\(\dfrac{5}{6}+\dfrac{9}{12}:\dfrac{18}{5}\)
\(=\dfrac{5}{6}+\dfrac{5}{24}\)
\(=\dfrac{25}{24}\)
\(---\)
\(\dfrac{5}{7}+\dfrac{9}{8}-\dfrac{15}{28}\)
\(=\dfrac{103}{56}-\dfrac{15}{28}\)
\(=\dfrac{73}{56}\)

5/6 + 9/12 : 18/5

=5/6 + 5/24

=25/24

\(\dfrac{5}{6}+\dfrac{9}{12}:\dfrac{18}{5}=\dfrac{5}{6}+\dfrac{5}{24}=\dfrac{25}{24}\)

\(\dfrac{5}{7}+\dfrac{9}{8}-\dfrac{15}{28}=\dfrac{40}{56}+\dfrac{72}{56}-\dfrac{30}{56}=\dfrac{41}{28}\)

giup mik voi

nhanh nhe

mik se k

mik se k cho

\(\left(8+\frac{2}{7}-\frac{1}{5}\right)-\left(9+\frac{5}{7}-\frac{6}{5}\right)+\left(\frac{3}{7}-\frac{7}{28}\right).\)

\(=8+\frac{2}{7}-\frac{1}{5}-9-\frac{5}{7}+\frac{6}{5}+\frac{3}{7}-\frac{7}{28}\)

\(=\frac{2}{7}-\frac{5}{7}+\frac{3}{7}-\frac{1}{5}+\frac{6}{5}+8-9-\frac{7}{28}\)

\(=1+8-9-\frac{7}{28}\)

\(=-\frac{7}{28}\)

7+8=8+7

17+4<17+7

7+8<7+9

17+6=6+17

7+5>7+3

17+28=28+17

a. - 7 - 9 = - (7 + 9) = - 16

b. - 15 - 8 = - (15 + 8) = - 23

c. - 28 - 32 = - (28 + 32) = - 60

d. - 43 - 32 = - (43 + 32) = - 75

e. - 5 - 9 - 11

= - (5 + 9 + 11)

= - (14 + 11)

= - 25

f. - 6 - 8 - 13

= - (6 + 8 + 13)

= - (14 + 13)

= - 27

g. - 3 - 7 - 25

= - (3 + 7 + 25)

= - (10 + 25)

= - 35

h. - 7 - 4 - 15

= - (7 + 4 + 15)

= - (11 + 15)

= - 26

5/7:15/28=4/3

9/11:21/22=6/7

7/9:5/6=14/15

8/15:16/25=5/6

k cho mình nhé

dung roi

a=4/3

b=6/7

c=14/15

d=5/6

5/7+9/8-15/28=1/17/56

\(\frac{5}{7}+\frac{9}{8}-\frac{15}{28}\)

\(=\frac{40}{56}+\frac{63}{56}-\frac{30}{56}\)

\(=\frac{40+63-30}{56}\)

\(=\frac{73}{56}\)

Phương pháp giải:

Cộng các số rồi điền kết quả vào chỗ trống.

Lời giải chi tiết:

6 + 7 = 13        7 + 8 = 15

8 + 9 = 17        17 + 6 = 23

28 + 7 = 35      39 + 8 = 47

30 + 4 = 34      60 + 6 = 66

8 + 50 = 58      5 + 16 = 21

4 + 27 = 31      5 + 38 = 43