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DT
19 tháng 7 2022

\(\dfrac{4}{5}+\dfrac{5}{7}.x=\dfrac{1}{6}\\ =>\dfrac{5}{7}.x=\dfrac{1}{6}-\dfrac{4}{5}=-\dfrac{19}{30}\\ =>x=-\dfrac{19}{30}:\dfrac{5}{7}\\ =>x=-\dfrac{133}{150}\)

7 tháng 4 2022

a)\(x=\left(\dfrac{3}{56}\cdot\dfrac{28}{9}\right):\dfrac{-3}{7}=\dfrac{1}{6}:\dfrac{-3}{7}=-\dfrac{7}{18}\)

b)\(x=\left(\dfrac{7}{15}\cdot\dfrac{5}{3}\right)+\dfrac{3}{16}=\dfrac{7}{9}+\dfrac{3}{16}=\dfrac{139}{144}\)

7 tháng 4 2022

c)\(x=\left(\dfrac{5}{6}-\dfrac{2}{5}\right).5=\dfrac{13}{6}\)

d)\(=>x\left(\dfrac{3}{4}-\dfrac{2}{5}\right)=\dfrac{1}{6}\cdot\left(\dfrac{3}{7}+\dfrac{5}{7}\right)\)

\(x\cdot\dfrac{7}{20}=\dfrac{4}{21}=>x=\dfrac{4}{21}\cdot\dfrac{20}{7}=\dfrac{80}{147}\)

AH
Akai Haruma
Giáo viên
9 tháng 5 2021

Lời giải:

a) 

$\frac{4}{7}x=\frac{2}{3}+\frac{1}{5}=\frac{13}{15}$

$x=\frac{13}{15}:\frac{4}{7}=\frac{91}{60}$

b) 

$\frac{5}{7}:x=\frac{1}{6}-\frac{4}{5}$

$\frac{5}{7}:x=\frac{-19}{30}$

$x=\frac{5}{7}:\frac{-19}{30}=\frac{-150}{133}$

a) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\) 

            \(\dfrac{4}{7}.x=\dfrac{1}{5}+\dfrac{2}{3}\) 

            \(\dfrac{4}{7}.x=\dfrac{13}{15}\) 

                \(x=\dfrac{13}{15}:\dfrac{4}{7}\) 

                \(x=\dfrac{91}{60}\) 

b) \(\dfrac{4}{5}+\dfrac{5}{7}:x=\dfrac{1}{6}\) 

            \(\dfrac{5}{7}:x=\dfrac{1}{6}-\dfrac{4}{5}\) 

            \(\dfrac{5}{7}:x=\dfrac{-19}{30}\) 

                  \(x=\dfrac{5}{7}:\dfrac{-19}{30}\) 

                 \(x=\dfrac{-150}{133}\)

19 tháng 5 2022

tách đi bạn

19 tháng 5 2022

a) (2x - 3)(6 - 2x) = 0

=> \(\left[{}\begin{matrix}2x-3=0\\6-2x=0\end{matrix}\right.=>\left[{}\begin{matrix}2x=3\\2x=6\end{matrix}\right.=>\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=3\end{matrix}\right.\)

b) \(5\dfrac{4}{7}:x=13=>\dfrac{39}{7}:x=13=>x=\dfrac{39}{7}:13=>x=\dfrac{3}{7}\)

c) \(2x-\dfrac{3}{7}=6\dfrac{2}{7}=>2x-\dfrac{3}{7}=\dfrac{44}{7}=>2x=\dfrac{47}{7}=>x=\dfrac{47}{14}\)

d) \(\dfrac{x}{5}+\dfrac{1}{2}=\dfrac{6}{10}=>\dfrac{x}{5}=\dfrac{6}{10}-\dfrac{1}{2}=>\dfrac{x}{5}=\dfrac{1}{10}=>x.10=5=>x=\dfrac{1}{2}\)

e) \(\dfrac{x+3}{15}=\dfrac{1}{3}=>\left(x+3\right).3=15=>x+3=5=>x=2\)

 

28 tháng 8 2021

a) \(x:\dfrac{6}{13}=\dfrac{13}{7}\\ \Rightarrow x=\dfrac{13}{7}.\dfrac{6}{13}\\ \Rightarrow x=\dfrac{6}{7}\)

b) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\\ \Rightarrow\dfrac{4}{7}.x=\dfrac{13}{15}\\ \Rightarrow x=\dfrac{91}{60}\)

c) \(\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\\ \Rightarrow\dfrac{3}{10}-x=\dfrac{6}{25}\\ \Rightarrow x=\dfrac{3}{50}\)

d) \(\dfrac{2}{3}x-\dfrac{7}{6}=\dfrac{5}{2}\\ \Rightarrow\dfrac{2}{3}x=\dfrac{11}{3}\\ \Rightarrow x=\dfrac{11}{2}\)

28 tháng 8 2021

đc!

25 tháng 3 2022

\(\dfrac{1}{5}+\dfrac{2}{11}< \dfrac{x}{55}< \dfrac{2}{5}+\dfrac{1}{5}\)

\(\dfrac{11+10}{55}< \dfrac{x}{55}< \dfrac{3}{5}\)

\(\dfrac{21}{55}< \dfrac{x}{55}< \dfrac{33}{55}\)

Vậy \(x\in\left\{22;23;24;...\right\}\)

 

25 tháng 3 2022

\(\dfrac{????????}{????????????}\)

8 tháng 9 2017

a.\(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)

\(\dfrac{5}{3}x-2\dfrac{1}{3}=\dfrac{5}{6}\)

\(\dfrac{5}{3}x=\dfrac{5}{6}+2\dfrac{1}{3}\)

\(\dfrac{5}{3}x=\dfrac{19}{6}\)

\(x=\dfrac{19}{5}:\dfrac{5}{3}\)

\(x=\dfrac{19}{10}\)

b. \(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)

\(2\dfrac{1}{6}:x+\dfrac{5}{8}=\dfrac{47}{63}\)

\(2\dfrac{1}{6}:x=\dfrac{47}{63}-\dfrac{5}{8}\)

\(2\dfrac{1}{6}:x=\dfrac{61}{504}\)

\(x=2\dfrac{1}{6}:\dfrac{61}{504}\)

\(x=\dfrac{1092}{61}\)

8 tháng 9 2017

a, \(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)

\(\Rightarrow\dfrac{5}{3}x=-\dfrac{3}{2}-\dfrac{2}{3}+2\dfrac{1}{3}=-\dfrac{3}{2}+2=\dfrac{1}{2}\)

\(\Rightarrow x=\dfrac{1}{2}:\dfrac{5}{3}=\dfrac{3}{10}\)

b, \(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)

\(\Rightarrow\dfrac{13}{6}:x=-\dfrac{7}{15}:\dfrac{21}{5}+\dfrac{6}{7}-\dfrac{5}{8}\)

\(\Rightarrow\dfrac{13}{6}:x=\dfrac{61}{504}\Rightarrow x=\dfrac{1092}{61}\)

c, \(\left(\dfrac{5}{6}x-0,3\right):2\dfrac{1}{3}=25\%\)

\(\Rightarrow\dfrac{5}{6}x-0,3=\dfrac{1}{4}.\dfrac{7}{3}\)

\(\Rightarrow\dfrac{5}{6}x=\dfrac{7}{12}+0,3=\dfrac{53}{60}\)

\(\Rightarrow x=\dfrac{53}{60}:\dfrac{5}{6}=1,06\)

d, \(\dfrac{4}{7}-\dfrac{2}{3}x=1,5+\dfrac{4}{5}x\)

\(\Rightarrow\dfrac{4}{5}x+\dfrac{2}{3}x=\dfrac{4}{7}-1,5\)

\(\Rightarrow\dfrac{22}{15}x=-\dfrac{13}{14}\Rightarrow x=-\dfrac{195}{308}\)

Chúc bạn học tốt!!!

3 tháng 6 2018

\(\dfrac{6:\dfrac{3}{5}-1\dfrac{1}{6}x\dfrac{6}{7}}{\dfrac{4}{5}x\dfrac{10}{11}+5\dfrac{2}{12}}=\left(10-x\right):\left(\dfrac{8}{11}x+\dfrac{31}{6}\right)\)

3 tháng 6 2018

\(\dfrac{10-\dfrac{7}{6}\cdot x\cdot\dfrac{6}{7}}{\dfrac{8}{11}\cdot x+\dfrac{31}{6}}=\dfrac{10-1\cdot x}{\dfrac{8}{11}\cdot x+\dfrac{31}{6}}=\dfrac{10-\dfrac{11}{11}\cdot x}{\dfrac{8}{11}\cdot x+\dfrac{31}{6}}=\dfrac{10-\dfrac{3}{11}\cdot x}{\dfrac{31}{6}}=>10-\dfrac{3}{11}\cdot x=\dfrac{31}{6} =>\dfrac{3}{11}\cdot x=10-\dfrac{31}{6}=\dfrac{29}{6}=>x=\dfrac{29}{6}:\dfrac{3}{11}=\dfrac{319}{18}\)

9 tháng 4 2022

a: x=4/27-2/3=4/27-18/27=-14/27

b: =>3/4x-1/4x=1/6+7/3

=>1/2x=1/6+14/6=5/2

hay x=5

c: =>13/10x=7/2+5/2=6

=>x=13/10:6=13/60

d: (3x+2)(-2/5x-7)=0

=>3x+2=0 hoặc 2/5x+7=0

=>x=-2/3 hoặc x=-35/2

a) x = 4/27 - 2/3

    x = -14/27

2:

a: =>2/3:x=1,4-2,4=-1

=>x=-2/3

b: =>x/5=25/30-19/30=6/30=1/5

=>x=1

3:

Số học sinh giỏi là 40*1/4=10 bạn

Số học sinh khá là 30*3/5=18 bạn

Số học sinh TB là 30-18=12 bạn