\(x-\frac{2}{5}=\frac{5}{7}\)

b) \(\frac...">

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22 tháng 7 2020

a, \(x-\frac{2}{5}=\frac{5}{7}\)

\(x=\frac{5}{7}+\frac{2}{5}\)

\(x=\frac{39}{35}\)

b, \(\frac{5}{12}-x=\frac{7}{18}\)

\(x=\frac{5}{12}-\frac{7}{18}\)

\(x=\frac{1}{36}\)

x-2/5=-5/2

x=-5/2+2/5

x=-21/10

vậy x=21/10

5/12-x=7/18

x=5/12-7/18

x=1/36

vậy x=1/35

câu b mình sai nên mình làm lại

5/12-x=7/18

x=5/12-7/18

x=1/36

vậy x=1/36

22 tháng 7 2020

a ) x - 2/5 = 5/7

     x          = 5/7 + 2/5

     x          = 39/35

b ) 5/12 - x = 7/18

                x = 5/12 - 7/18

                x = 1/36

22 tháng 7 2020

a)  X -  2/5  = 5/7

     X           = 5/7 + 2/5

     X           =  39/35

b) 5/12 - X = 7/18

              X = 5/12 - 7/18

              X = 1/36

22 tháng 7 2020

a, \(x-\frac{2}{5}=\frac{5}{7}\Leftrightarrow x=\frac{39}{35}\)

b, \(\frac{5}{12}-x=\frac{7}{18}\Leftrightarrow x=\frac{1}{36}\)

@Hoc tot!@

17 tháng 4 2019

a)\(\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)

\(=\frac{-7}{25}.\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=\frac{-7}{25}.1-\frac{18}{25}\)

\(=-\frac{7}{25}-\frac{18}{25}\)

\(=-1\)

17 tháng 4 2019

b)\(\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{12}\)

\(=\frac{5}{7}.\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)\)

\(=\frac{5}{7}.\left(\frac{4}{12}-\frac{3}{12}-\frac{1}{12}\right)\)

\(=\frac{5}{7}.0\)

\(=0\)

10 tháng 1

A = (19\(\frac58\) : \(\frac{7}{12}\) - 13\(\frac14\): \(\frac72\)) x \(\frac45\) (xem lại đề bài)

B = (9\(\frac{30303}{80808}\) + 7\(\frac{303030}{808080}\)) + 4,03

B = (9\(\frac38\) + 7\(\frac38\)) + 4,03

B =(9 + 7) + (\(\frac38+\frac38\)) + 4,03

B = 16 + 3/4 + 4,03

B = 16 + 0,75 + 4,03

B = 16,75 + 4,03

B = 20,78

18 tháng 4 2018

a) \(x-\frac{5}{7}=\frac{1}{9}\Rightarrow x=\frac{1}{9}+\frac{5}{7}\Rightarrow x=\frac{52}{63}\)

b) \(\frac{-3}{7}-x=\frac{4}{5}+\frac{-2}{3}\Rightarrow\frac{-3}{7}-x=\frac{2}{15}\Rightarrow x=\frac{-3}{7}-\frac{2}{15}\Rightarrow x=\frac{-59}{105}\)

c) \(x-\frac{1}{5}=\frac{2}{7}.\frac{-11}{5}\Rightarrow x-\frac{1}{5}=\frac{-22}{35}\Rightarrow x=\frac{-22}{35}+\frac{1}{5}\Rightarrow x=\frac{-3}{7}\)

d) \(\frac{x}{182}=\frac{-6}{14}.\frac{35}{91}\Rightarrow\frac{x}{182}=\frac{-15}{91}\Rightarrow x=\frac{\left(-15\right).182}{91}\Rightarrow x=-30\)

10 tháng 1

0,7.2\(\frac23\).20.0,375.\(\frac{5}{28}\)

= \(\frac{7}{10}\) .\(\frac83\).20.\(\frac38\).\(\frac{5}{28}\)

= (\(\frac{7}{10}\).\(\frac{5}{28}\).20).(\(\frac83\).\(\frac38\))

= (\(\frac18.20\)). 1

= \(\frac52\)

10 tháng 1

B = (9,75 .21\(\frac37\) + \(\frac{39}{4}\).18\(\frac47\))

B = (\(\frac{39}{4}\).\(\frac{150}{7}\frac{}{7}\)+ \(\frac{39}{4}\).\(\frac{130}{7}\))

B = \(\frac{39}{4}\).(\(\frac{150}{7}\) + \(\frac{130}{7}\))

B = \(\frac{39}{4}\).\(\frac{280}{7}\)

B = 390

4 tháng 7 2016

a/ \(\frac{6}{7}x=\frac{18}{23}\)

\(x=\frac{18}{23}:\frac{6}{7}=\frac{21}{23}\)

b/ \(2\frac{1}{2}x=\frac{5}{6}\)

\(=>\frac{5}{2}x=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{5}{2}=\frac{1}{3}\)

c/\(x:2\frac{3}{4}=9\frac{5}{8}\)

\(x:\frac{11}{4}=\frac{77}{8}\)

\(x=\frac{77}{8}\cdot\frac{11}{4}=\frac{847}{32}\)

d/\(7\frac{1}{7}\cdot\frac{1}{7}\cdot x=22\frac{1}{8}\)

\(\frac{50}{49}x=\frac{177}{8}\)

\(x=\frac{177}{8}:\frac{50}{49}=\frac{8673}{400}\)

4 tháng 7 2016

\(a,\frac{6}{7}.x=\frac{18}{23}\) \(\Rightarrow x=\frac{18}{23}:\frac{6}{7}=\frac{18}{23}.\frac{7}{6}=\frac{21}{23}\)

\(b,2\frac{1}{2}.x=\frac{5}{6}\Rightarrow\frac{5}{2}.x=\frac{5}{6}\Rightarrow x=\frac{5}{6}:\frac{5}{2}=\frac{5}{6}.\frac{2}{5}=\frac{1}{3}\)

\(c,x:2\frac{3}{4}=9\frac{5}{8}\Rightarrow x:\frac{11}{4}=\frac{77}{8}\Rightarrow x=\frac{77}{8}.\frac{11}{4}=\frac{847}{32}\)

\(d,7\frac{1}{7}.\frac{1}{7}.x=22\frac{1}{8}\Rightarrow\frac{50}{49}.x=\frac{177}{8}\Rightarrow x=\frac{177}{8}:\frac{50}{49}=\frac{177}{8}.\frac{49}{50}=\frac{8673}{400}\)

28 tháng 2 2019

giúp mk nhanh nhé

ai nhanh mk tk cho

28 tháng 2 2019

B1

a) \(1-\left(5\frac{3}{8}+x-7\frac{5}{24}\right):16\frac{2}{3}=0\)

\(1-\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{50}{3}=0\)

\(1-\left(x-\frac{11}{6}\right).\frac{3}{50}=0\)

\(\left(x-\frac{11}{6}\right).\frac{3}{50}=1-0\)

\(\left(x-\frac{11}{6}\right).\frac{3}{50}=1\)

\(x-\frac{11}{6}=1:\frac{3}{50}\)

\(x-\frac{11}{6}=\frac{50}{3}\)

\(x=\frac{50}{3}+\frac{11}{6}\)

\(x=\frac{37}{2}\)

b) \(\frac{3}{5}+\frac{5}{7}:x=\frac{1}{3}\)

\(\frac{5}{7}:x=\frac{1}{3}-\frac{3}{5}\)

\(\frac{5}{7}:x=-\frac{4}{15}\)

\(x=\frac{5}{7}:\left(-\frac{4}{15}\right)\)

\(x=-\frac{75}{28}\)

c) \(\left(4\frac{1}{2}-\frac{2}{5}.x\right):\frac{7}{4}=\frac{11}{9}\)

\(\left(\frac{9}{2}-\frac{2}{5}.x\right):\frac{7}{4}=\frac{11}{9}\)

\(\frac{9}{2}-\frac{2}{5}.x=\frac{11}{9}.\frac{7}{4}\)

\(\frac{9}{2}-\frac{2}{5}.x=\frac{11}{2}\)

\(\frac{2}{5}.x=\frac{9}{2}-\frac{11}{2}\)

\(\frac{2}{5}.x=-1\)

\(x=-1:\frac{2}{5}\)

\(x=-\frac{5}{2}\)

B2

a) \(\left(\frac{1}{2}+\frac{1}{3}+\frac{2}{6}\right).24:5-\frac{9}{22}:\frac{15}{121}\)

\(=\left(\frac{3}{6}+\frac{2}{6}+\frac{2}{6}\right).24:5-\frac{9}{22}.\frac{121}{15}\)

\(=\frac{7}{6}.24:5-\frac{33}{10}\)

\(=28:5-\frac{33}{10}\)

\(=\frac{28}{5}-\frac{33}{10}\)

\(=\frac{56}{10}-\frac{33}{10}\)

\(=\frac{23}{10}\)

b) \(\frac{5}{14}+\frac{18}{35}+\left(1\frac{1}{4}-\frac{5}{4}\right):\left(\frac{5}{12}\right)^2\)

\(=\frac{25}{70}+\frac{36}{70}+\left(\frac{5}{4}-\frac{5}{4}\right):\frac{25}{144}\)

\(=\frac{61}{70}+0:\frac{25}{144}\)

\(=\frac{61}{70}+0\)

\(=\frac{61}{70}\)

27 tháng 10 2025

Tìm \(x\) câu a:

\(\frac13.x\) + \(\frac25.\left(x+1\right)\) = 0

\(\frac{5}{15}x\) + \(\frac{6}{15}x\) + \(\frac25\) = 0

\(\frac{11}{15}x\) = - \(\frac25\)

\(x=-\frac25:\frac{11}{15}\)

\(x\) = - \(\frac25\times\frac{15}{11}\)

\(x\) = - \(\frac{6}{11}\)

Vậy \(x=-\frac{6}{11}\)

27 tháng 10 2025

Tìm \(x\) câu b:

\(x\) x 25% = 0,5

\(x\times0,25\) = 0,5

\(x=0,5:0,25\)

\(x=2\)

Vậy \(x=2\)

17 tháng 3

Câu 1a:

1/3x + 2/5(x + 1) = 0

1/3x + 2/5x + 2/5 = 0

1/3x + 2/5x = - 2/5

x(1/3 + 2/5) = -2/5

x.(5/15 + 6/15) = -2/5

x.11/15 = - 2/5

x = - 2/5 : 11/15

x = - 6/11

Vậy x = -6/11



17 tháng 3

Câu b:

x . 25%. x = 0,5

x.x = 0,5 : 25%

x^2 = 2

x = - \(\sqrt2\); x = \(\sqrt2\)

Vậy x ∈ {- \(\sqrt2\); \(\sqrt2\) )