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30 tháng 11 2021

bang 73/63

30 tháng 11 2021

\(\frac{5}{7}+\frac{4}{9}=\frac{73}{63}\)

14 tháng 4 2016

có ai biết bài này không xin trả lời dùm 

10 tháng 5 2021

18 chia 2phaan 3

Ta có: \(\dfrac{5}{9}+\dfrac{13}{7}+\dfrac{15}{3}+\dfrac{8}{7}+\dfrac{4}{9}+\dfrac{11}{13}\)

\(=\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\left(\dfrac{13}{7}+\dfrac{8}{7}\right)+5\dfrac{11}{13}\)

\(=9+\dfrac{11}{13}\)

\(=\dfrac{128}{13}\)

9 tháng 7 2021

what

17 tháng 4 2017

3/8+9/5=87/40

2-5/6=7/6

5/7-4/9=17/63

7/8+3/4=13/8

17 tháng 4 2017

\(\frac{3}{8}+\frac{9}{5}=\frac{15}{40}+\frac{72}{40}=\frac{87}{40}\)

\(\frac{5}{7}-\frac{4}{9}=\frac{45}{63}-\frac{28}{63}=\frac{17}{63}\)

\(2-\frac{5}{6}=\frac{12}{6}-\frac{5}{6}=\frac{7}{6}\)

\(\frac{7}{8}+\frac{3}{4}=\frac{7}{8}+\frac{6}{8}=\frac{13}{8}\)

21 tháng 9 2020

                                                            Bài giải

\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\)

\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{394}{90}\)

\(\frac{15}{17}-\frac{11}{13}+\frac{3}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)

\(\frac{9}{12}\text{ x }\frac{4}{3}\text{ : }\frac{8}{5}=\frac{9}{12}\text{ x }\frac{4}{3}\text{ x }\frac{5}{8}=\frac{9\text{ x }4\text{ x }5}{12\text{ x }3\text{ x }8}=\frac{5}{8}\)

\(\frac{4}{5}\text{ x }\frac{15}{8}\text{ : }\frac{5}{7}=\frac{4}{5}\text{ x }\frac{15}{8}\text{ x }\frac{7}{5}=\frac{4\text{ x }15\text{ x }7}{5\text{ x }8\text{ x }5}=\frac{21}{10}\)

26 tháng 4 2021

\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\) 

\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{197}{45}\)

\(\frac{15}{17}-\frac{11}{13}+\frac{1}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)

\(\frac{9}{12}\times\frac{4}{3}:\frac{8}{5}=1:\frac{8}{5}=\frac{5}{8}\)

\(\frac{4}{5}\times\frac{15}{8}:\frac{5}{7}=\frac{3}{2}:\frac{5}{7}=\frac{21}{10}\)

18 tháng 7 2023

\(C=\dfrac{3}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{3}{7}-\dfrac{3}{7}\)

\(=\dfrac{3}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{3}{7}-\dfrac{3}{7}\times1\)

\(=\dfrac{3}{7}\times\left(\dfrac{5}{9}+\dfrac{4}{9}-1\right)\)

\(=\dfrac{3}{7}\times0=0\)

\(D=8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)\)

\(=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)\)

\(=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}\)

\(=\left(\dfrac{58}{7}-\dfrac{30}{7}\right)-\dfrac{31}{9}\)

\(=4-\dfrac{31}{9}=\dfrac{36}{9}-\dfrac{31}{9}\)

\(=\dfrac{5}{9}\)

16 tháng 7 2023

` a)  4 8/23 + 5 7/8 - 9 8/23 `

 

`= 100/23 + 47/8 - 215/23 `

 

`= ( 100/23 - 215/23) + 47/8 `

 

`= -115/23 + 47/8 `

 

`= -5 + 47/8 `

 

`= -5/1 + 47/8 `

 

`= -40/8 + 47/8 `

 

`=7/8`

 

`b) 8 2/7 - ( 3 4/9 + 4 2/7 ) `

 

`= 58/7 - 31/9 - 30/7 `

 

`= (58/7 - 30/7 ) - 31/9 `

 

`= 28/7 - 31/9 `

 

` = 252/63 - 217/63 `

 

`= 35/63`

 

`= 5/9`

 

`@ animephamdanhv.`

16 tháng 7 2023

a)\(4\dfrac{8}{23}+5\dfrac{7}{8}-9\dfrac{8}{23}=\dfrac{100}{23}+\dfrac{47}{8}-\dfrac{215}{23}=\dfrac{100}{23}-\dfrac{215}{23}+\dfrac{47}{8}=-\dfrac{115}{23}+\dfrac{47}{8}=-5+\dfrac{47}{8}=\dfrac{7}{8}\)

b) \(8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}=\dfrac{58}{7}-\dfrac{30}{7}-\dfrac{31}{9}=4-\dfrac{31}{9}=\dfrac{5}{9}\)

7 tháng 5 2017

a) 7/10 - y × 3/4 = 1/5

                y × 3/4 = 7/10 - 1/5

                y × 3/4 = 1/2

                          y = 1/2 : 3/4

                          y = 2/3. Vậy y = 2/3

b) 5/6 : ( y + 7/9 ) = 3/4

                  y + 7/9 = 5/6 : 3/4

                  y + 7/9 = 10/9

                            y. = 10/9 - 7/9

                            y = 1/3. Vậy y = 1/3

\(\frac{7}{10}\)- y * \(\frac{3}{4}\)\(\frac{1}{5}\)

y * \(\frac{3}{4}\)\(\frac{7}{10}\)\(\frac{1}{5}\)

y * \(\frac{3}{4}\)\(\frac{1}{2}\)

y = \(\frac{1}{2}\)\(\frac{3}{4}\)

y = \(\frac{2}{3}\)

Vậy y = \(\frac{2}{3}\)

\(\frac{5}{6}\): ( y + \(\frac{7}{9}\)) = \(\frac{3}{4}\)

y + \(\frac{7}{9}\) = \(\frac{5}{6}\)\(\frac{3}{4}\)

y + \(\frac{7}{9}\) = \(\frac{10}{9}\)

y = \(\frac{10}{9}\)\(\frac{7}{9}\)

y = \(\frac{3}{9}\)

Vậy y = \(\frac{3}{9}\)

20 tháng 5 2021

7/9 + 4/5 + 2/9 + 1/5

= ( 7/9 + 2/9 ) + ( 4/5 + 1/5 )

=        1           +       1

= 2 

~ Hok T ~

8 tháng 5 2022

4/5=0,8

7/2=3,5

9/4=2,25

9/25=0,36

8 tháng 5 2022

\(\dfrac{4}{5}=0,8\)

\(\dfrac{7}{2}=3,5\)

\(\dfrac{9}{4}=2,25\)

\(\dfrac{9}{25}=0,36\)