a) \(\dfrac{3}{7}\)

b)\(\dfrac{9}{4}\)

c)\(\dfrac{1}{3}\)

d)\(\dfrac{41}{32}\) 

e)\(\dfrac{73}{60}\)

a,3/7

b,9/4

c,1/3

d,41/32

e,73/60

a) 5 : 3/4 - 4 4/5 : 3/4

= 5 . 4/3 - 24/5 . 4/3

= (5 - 24/5) . 4/3

= 1/5 × 4/3

= 4/15

b) -3/5 . 2/7 + (-3/7) . 3/5 + (-3/7)

= (-3/7) . (2/5 + 3/5 + 1)

= (-3/7) . 2

= -6/7

c) [(-4 2/7) . 7/11 + 7/11 . (5 1/3)] . 5 - 5 2/3

= (-30/7 . 7/11 + 7/11 . 16/3) . 5 - 17/3

= (-30/11 + 112/33) . 5 - 17/3

= 2/3 . 5 - 17/3

= 10/3 - 17/3

= -7/3

d) 5/39 . [(7 4/5) . (1 2/3) + (8 1/3) . (7 4/5)]

= 5/39 . (39/5 . 5/3 + 25/3 . 39/5)

= 5/39 . 39/5 . (5/3 + 25/3)

= 1 . 10

= 10

= 

   [4\(\dfrac{1}{5}\) - 2\(\dfrac{2}{5}\)] x 8\(\dfrac{5}{6}\)

= [\(\dfrac{21}{5}\) - \(\dfrac{12}{5}\)] x \(\dfrac{53}{6}\)

= \(\dfrac{9}{5}\) x \(\dfrac{53}{6}\)

= \(\dfrac{159}{10}\)

   [5\(\dfrac{1}{3}\) - 2\(\dfrac{2}{3}\)]: \(\dfrac{3}{7}\)

= [\(\dfrac{16}{3}\) - \(\dfrac{8}{3}\)]: \(\dfrac{3}{7}\)

= \(\dfrac{8}{3}\) : \(\dfrac{3}{7}\)

= \(\dfrac{56}{9}\)

   5\(\dfrac{3}{10}\) x \(\dfrac{1}{4}\): 2\(\dfrac{4}{7}\)

= \(\dfrac{53}{10}\) x \(\dfrac{1}{4}\): \(\dfrac{18}{7}\)

= \(\dfrac{53}{10}\) x \(\dfrac{1}{4}\) x \(\dfrac{7}{18}\)

= \(\dfrac{371}{720}\)

a) 72/45 x 35/36= 8/5 x 35/36 =280/180=14/9.

b)1/2:3/4+1/6:3/4 =(1/2+1/6) : 3/4 =8/12:3/4 = 24/36=2/3

c) 2/3x4/5+1/3=2/3+1/3x4/5+1/3=4/3x4/15=16/45.

Nếu sai thông cảm cho mình nhé. Bạn ko k cũng ko sao đâu.

Bạn ko k cũng ko sao đâu.

a: \(=\dfrac{10-6}{15}\cdot\dfrac{1}{3}=\dfrac{4}{45}\)

b: \(=\dfrac{10+6}{15}\cdot\dfrac{1}{3}=\dfrac{16}{45}\)

c: \(=\dfrac{4+3}{6}\cdot\dfrac{4}{3}=\dfrac{7\cdot4}{6\cdot3}=\dfrac{28}{18}=\dfrac{14}{9}\)

d: \(=\dfrac{20-14}{35}\cdot\dfrac{9}{4}=\dfrac{6}{35}\cdot\dfrac{9}{4}=\dfrac{54}{140}=\dfrac{27}{70}\)

a (2/3 - 2/5 ) nhân 1/3

C1) 

=4/15 x 1/3

= 4/45

C2)

2/3 x 1/3 - 2/5 x 1/3

= 2/9 - 2/15

= 4/45

b (2/3 + 2/5 )nhân 1/3

GIỐNG CÂU A

c (2/3 + 1/2 ) chia 3/4

C1) =7/6 : 3/4

= 14/9

C2) 

2/3 : 3/4 + 1/2 : 3/4

= 8/9 + 2/3

= 14/9

d(4/7 - 2/5 ) chia 4/9

C1) 

= 6/35 : 4/9

= 27/70

C2)

4/7 : 4/9 - 2/5 : 4/9

= 9/7 -9/10

= 27/70

a) C1 : \(\left(\dfrac{2}{3}-\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{4}{15}\times\dfrac{1}{3}=\dfrac{4}{45}\)

    C2 : \(\left(\dfrac{2}{3}-\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{1}{3}-\dfrac{2}{5}\times\dfrac{1}{3}=\dfrac{2}{9}-\dfrac{2}{15}=\dfrac{4}{45}\)

b) C1 \(\left(\dfrac{2}{3}+\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{16}{15}\times\dfrac{1}{3}=\dfrac{16}{45}\)

    C2 \(\left(\dfrac{2}{3}+\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{1}{3}+\dfrac{2}{5}\times\dfrac{1}{3}=\dfrac{2}{9}+\dfrac{2}{15}=\dfrac{16}{45}\)

c) C1 \(\left(\dfrac{2}{3}+\dfrac{1}{2}\right):\dfrac{3}{4}=\left(\dfrac{2}{3}+\dfrac{1}{2}\right)\times\dfrac{4}{3}=\dfrac{7}{6}\times\dfrac{4}{3}=\dfrac{14}{9}\)

   C2 \(\left(\dfrac{2}{3}+\dfrac{1}{2}\right):\dfrac{3}{4}=\left(\dfrac{2}{3}+\dfrac{1}{2}\right)\times\dfrac{4}{3}=\dfrac{2}{3}\times\dfrac{4}{3}+\dfrac{1}{2}\times\dfrac{4}{3}=\dfrac{8}{9}+\dfrac{2}{3}=\dfrac{14}{9}\)

d) C1 \(\left(\dfrac{4}{7}-\dfrac{2}{5}\right):\dfrac{4}{9}=\left(\dfrac{4}{7}-\dfrac{2}{5}\right)\times\dfrac{9}{4}=\dfrac{6}{35}\times\dfrac{9}{4}=\dfrac{27}{70}\)

    C2 \(\left(\dfrac{4}{7}-\dfrac{2}{5}\right):\dfrac{4}{9}=\left(\dfrac{4}{7}-\dfrac{2}{5}\right)\times\dfrac{9}{4}=\dfrac{4}{7}\times\dfrac{9}{4}-\dfrac{2}{5}\times\dfrac{9}{4}=\dfrac{36}{28}-\dfrac{9}{10}=\dfrac{27}{70}\)

có ai biết bài này không xin trả lời dùm 

18 chia 2phaan 3

hihi tớ ko hiểu đâu cậu viết dài và khó hiểu quá

bạn ghi + - x : nhá

Câu 1:

a. $3\frac{2}{3}+2\frac{1}{2}=(3+2)+(\frac{2}{3}+\frac{1}{2})=5+\frac{7}{6}=6+\frac{1}{6}=6\frac{1}{6}$

b. \(2\frac{1}{2}\times 3\frac{2}{5}=\frac{5}{2}\times \frac{17}{5}=\frac{17}{2}\)

c.

\(3\frac{1}{3}: 4\frac{1}{4}=\frac{10}{3}: \frac{17}{4}=\frac{40}{51}\)

d.

\(3\frac{1}{2}+4\frac{5}{7}-5\frac{5}{14}=(3+4-5)+(\frac{1}{2}+\frac{5}{7}-\frac{5}{14})=2+\frac{6}{7}=2\frac{6}{7}\)

Câu 2:

a. $x\times \frac{2}{7}=\frac{6}{11}$

$x=\frac{6}{11}: \frac{2}{7}=\frac{21}{11}$

b. $x: \frac{3}{2}=\frac{1}{4}$

$x=\frac{1}{4}\times \frac{3}{2}=\frac{3}{8}$

Câu 3:

Coi số lớn là 5 phần thì số bé là 3 phần. Hiệu số phần bằng nhau là:
$5-3=2$ (phần)

Số lớn là: $36:2\times 5=90$

Số bé là: $36:2\times 3=54$

BẠN VIẾT RÕ RÀNG RA NHÉ ~~^^

tên rõ hay

t

\(\frac{2}{3}\)x \(\frac{5}{8}\)x \(\frac{8}{15}\)= \(\frac{2}{3}\)x \(\frac{1}{15}\)= \(\frac{2}{45}\)

\(\frac{22}{5}\)x \(12\)x \(\frac{20}{40}\)= \(\frac{22}{5}\)x \(12\)x \(\frac{1}{2}\)= \(\frac{22}{5}\)x 6 = \(\frac{122}{5}\)

\(\frac{7}{2}\)x \(\frac{26}{7}\)x \(\frac{4}{13}\)= \(\frac{91}{7}\)x \(\frac{4}{13}\)