Tính:a) $\dfrac{3}{8} \dfrac{7}{8}$ b) $\dfrac{7}{9}-\dfrac{4}{9}$ c) $\dfrac{5}{6} \dfrac{1}{8}$ d) \(\dfrac{9}{15}-\dfrac{2}...

1

NL

Nguyễn Lê Phước Thịnh

29 tháng 10 2023

a: $\dfrac{3}{8}+\dfrac{7}{8}=\dfrac{3+7}{8}=\dfrac{10}{8}=\dfrac{5}{4}$

b: $\dfrac{7}{9}-\dfrac{4}{9}=\dfrac{7-4}{9}=\dfrac{3}{9}=\dfrac{1}{3}$

c: $\dfrac{5}{6}+\dfrac{1}{8}=\dfrac{20}{24}+\dfrac{3}{24}=\dfrac{20+3}{24}=\dfrac{23}{24}$

d: $\dfrac{9}{15}-\dfrac{2}{5}=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{3-2}{5}=\dfrac{1}{5}$

e: $\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}=\dfrac{2+3+9}{5}=\dfrac{14}{5}$

g: $\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}=\dfrac{8-1-3}{10}=\dfrac{4}{10}=\dfrac{2}{5}$

h: $\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}=\dfrac{23-4+2}{7}=\dfrac{21}{7}=3$

Tính:a) $\dfrac{5}{9}:\dfrac{7}{3}$ b) $\dfrac{2}{7}:\dfrac{8}{5}$ c) $\dfrac{4}{15}:\dfrac{2}{5}$ ...

D

datcoder

Giáo viên

31 tháng 10 2023

1

HQ

Hà Quang Minh

Giáo viên

27 tháng 11 2023

a) $\frac{5}{9}:\frac{7}{3} = \frac{5}{9} \times \frac{3}{7} = \frac{{15}}{{63}} = \frac{5}{{21}}$

b) $\frac{2}{7}:\frac{8}{5} = \frac{2}{7} \times \frac{5}{8} = \frac{{10}}{{56}} = \frac{5}{{28}}$

c) $\frac{4}{{15}}:\frac{2}{5} = \frac{4}{{15}} \times \frac{5}{2} = \frac{{20}}{{30}} = \frac{2}{3}$

d) $\frac{7}{9}:\frac{{21}}{9} = \frac{7}{9} \times \frac{9}{{21}} = \frac{{63}}{{189}} = \frac{1}{3}$

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KJ

❖ Khang/GD❄ 『ʈєɑɱ❖Hoàng๖ۣۜGia☆』

22 tháng 2 2022

Tính:

a, $\dfrac{3}{5}+\dfrac{-4}{9}$ b, $\dfrac{3}{5}+\dfrac{2}{5}.\dfrac{15}{8}$

c, $\dfrac{7}{2}.\dfrac{8}{13}+\dfrac{8}{13}.\dfrac{-5}{2}+\dfrac{8}{13}$

d, $\dfrac{-5}{17}.\dfrac{-9}{23}+\dfrac{9}{23}.\dfrac{-22}{17}+11\dfrac{9}{23}$

#Toán lớp 6

2

NL

Nguyễn Lê Phước Thịnh

22 tháng 2 2022

a: =27/45-20/45=7/45

b: $=\dfrac{3}{5}+\dfrac{30}{40}=\dfrac{3}{5}+\dfrac{3}{4}=\dfrac{12}{20}+\dfrac{15}{20}=\dfrac{27}{20}$

c: $=\dfrac{8}{13}\left(\dfrac{7}{2}-\dfrac{5}{2}+1\right)=\dfrac{8}{13}\cdot2=\dfrac{16}{13}$

d: $=\dfrac{9}{23}\left(\dfrac{5}{17}-\dfrac{22}{17}\right)+11+\dfrac{9}{23}=11$

R

Rhider

22 tháng 2 2022

a) $\dfrac{3}{5}+\dfrac{-4}{9}=\dfrac{27}{45}+\dfrac{-20}{45}=\dfrac{7}{45}$

b) $\dfrac{3}{5}+\dfrac{2}{5}.\dfrac{15}{8}=1.\dfrac{15}{8}=\dfrac{15}{8}$

c) $\dfrac{7}{2}.\dfrac{8}{13}+\dfrac{8}{13}.\dfrac{-5}{2}+\dfrac{8}{13}=\dfrac{8}{13}.\left(\dfrac{7}{2}+\dfrac{-5}{2}\right)=\dfrac{8}{13}.1=\dfrac{8}{13}$

d) $\dfrac{-5}{17}.\dfrac{-9}{23}+\dfrac{9}{23}.\dfrac{-22}{17}+11\dfrac{9}{23}=\dfrac{9}{23}.\left(\dfrac{-5}{17}+\dfrac{-22}{17}\right)=\dfrac{-243}{391}$

Tính:a) $\dfrac{7}{3}+\dfrac{4}{9}$ b) $\dfrac{3}{14}+6$ c) $\dfrac{7}{8}-\dfrac{1}{2}$ ...

D

datcoder

Giáo viên

31 tháng 10 2023

Tính:a) $\dfrac{-5}{9}$$+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}$ b)$\left(\dfrac{-5}{12}+\dfrac{6}{11}\right)+\left(\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}\right)$c) A= $49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)$d)...

1

NL

Nguyễn Lê Phước Thịnh

31 tháng 10 2023

a: $\dfrac{7}{3}+\dfrac{4}{9}=\dfrac{21}{9}+\dfrac{4}{9}=\dfrac{21+4}{9}=\dfrac{25}{9}$

b: $\dfrac{3}{14}+6=\dfrac{3+6\cdot14}{14}=\dfrac{84+3}{14}=\dfrac{87}{14}$

c: $\dfrac{7}{8}-\dfrac{1}{2}=\dfrac{7}{8}-\dfrac{4}{8}=\dfrac{7-4}{8}=\dfrac{3}{8}$

d: $5-\dfrac{9}{10}=\dfrac{50}{10}-\dfrac{9}{10}=\dfrac{50-9}{10}=\dfrac{41}{10}$

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QA

Quỳnh Anh Daisy

25 tháng 7 2021

#Toán lớp 6

3

OY

OH-YEAH^^

25 tháng 7 2021

a) $\dfrac{-5}{9}+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}$

=$\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)+\left(\dfrac{8}{15}+\dfrac{7}{15}\right)+\dfrac{-2}{11}$

=$\left(-1\right)+1+\dfrac{-2}{11}$

=$\dfrac{-2}{11}$

b) $\left(\dfrac{-5}{12}+\dfrac{6}{11}\right)+\left(\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}\right)$

=$\dfrac{-5}{12}+\dfrac{6}{11}+\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}$

=$\left(\dfrac{-5}{12}+\dfrac{5}{12}\right)+\left(\dfrac{6}{11}+\dfrac{5}{11}\right)+\dfrac{7}{17}$

=$0+0+\dfrac{7}{17}$

=$\dfrac{7}{17}$

c) A= $49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)$

A=$49\dfrac{8}{23}-5\dfrac{7}{32}-14\dfrac{8}{23}$

A=$\left(49\dfrac{8}{23}-14\dfrac{8}{23}\right)-5\dfrac{7}{32}$

A=$35-5\dfrac{7}{32}$

A=$35-\dfrac{167}{32}=\dfrac{953}{32}$

d) C=$\dfrac{-3}{7}.\dfrac{5}{9}+\dfrac{4}{9}.\dfrac{-3}{7}+2\dfrac{3}{7}$

C=$\dfrac{-3}{7}.\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{17}{7}$

C=$\dfrac{-3}{7}.1+\dfrac{17}{7}$

C=$\dfrac{-3}{7}+\dfrac{17}{7}=2$

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HD

Hải Đức

25 tháng 7 2021

a, `(-5)/9+8/15+(-2)/11+4/(-9)+7/15`

`=-5/9+8/15-2/11-4/9+7/15`

`=(-5/9-4/9)+(8/15+7/15)-2/11`

`=-9/9+15/15-2/11`

`=-1+1-2/11`

`=-2/11`

b, `((-5)/12+6/11)+(7/17+5/11+5/12)`

`=-5/12+6/11+7/17+5/11+5/12`

`=(-5/12+5/12)+(6/11+5/11)+7/17`

`=0+11/11+7/17`

`=1+7/17`

`=17/17+7/17`

`=24/17`

c, `A=49 8/23 - (5 7/32 + 14 8/23)`

`A=49 8/23 - 5 7/32 - 14 8/23`

`A=(49 8/23 - 14 8/23)-5 7/32`

`A=35 - 167/32`

`A=953/32`

d, `C=(-3)/7.5/9+4/9.(-3)/7+2 3/7`

`C=-3/7 . 5/9-4/9 . 3/7+17/7`

`C=-3/7.(5/9+4/9)+17/7`

`C=-3/7 . 1+17/7`

`C=2`

Tính:a) $\dfrac{1}{7}+\dfrac{2}{7}+\dfrac{3}{7}$ b) $\dfrac{2}{9}+\dfrac{5}{9}+\dfrac{8}{9}$c) $\dfrac{13}{14}-\dfrac{5}{14}-\dfrac{1}{14}$ ...

D

datcoder

Giáo viên

28 tháng 10 2023

1

GT

Giáp Thị Hiền Lương

28 tháng 10 2023

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Tính:a) $\dfrac{2}{5}\times\dfrac{3}{8}\times\dfrac{3}{4}$ b) $\dfrac{1}{3}\times\dfrac{1}{6}\times\dfrac{1}{9}$c) $\dfrac{3}{4}:\dfrac{1}{5}:\dfrac{7}{8}$ ...

D

datcoder

Giáo viên

31 tháng 10 2023

Tính:a) $\dfrac{2}{3}+\dfrac{4}{3}$ $\dfrac{9}{8}-\dfrac{1}{8}$ $\dfrac{1}{6}+\dfrac{2}{3}$ $\dfrac{3}{4}-\dfrac{7}{16}$b) $9+\dfrac{2}{7}$ $\dfrac{3}{8}+10$ $7-\dfrac{2}{11}$ $\dfrac{25}{4}-5$c) $\dfrac{2}{3}\times\dfrac{1}{4}$ $\dfrac{7}{11}\times\dfrac{11}{2}$ $\dfrac{3}{7}:\dfrac{4}{9}$ ...

1

HQ

Hà Quang Minh

Giáo viên

27 tháng 11 2023

a) $\frac{2}{5} \times \frac{3}{8} \times \frac{3}{4} = \frac{{2 \times 3 \times 3}}{{5 \times 8 \times 4}} = \frac{{18}}{{160}} = \frac{9}{{80}}$

b) $\frac{1}{3} \times \frac{1}{6} \times \frac{1}{9} = \frac{{1 \times 1 \times 1}}{{3 \times 6 \times 9}} = \frac{1}{{162}}$

c) $\frac{3}{4}:\frac{1}{5}:\frac{7}{8} = \frac{3}{4} \times \frac{5}{1} \times \frac{8}{7} = \frac{{3 \times 5 \times 8}}{{4 \times 1 \times 7}} = \frac{{120}}{{28}} = \frac{{30}}{7}$

d) $\frac{3}{5}:\frac{1}{5}:\frac{3}{8} = \frac{3}{5} \times \frac{5}{1} \times \frac{8}{3} = \frac{{3 \times 5 \times 8}}{{5 \times 1 \times 3}} = 8$

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D

datcoder

Giáo viên

31 tháng 10 2023