TÌM X À

Đunga rồi >< mình nhầm. Đây toán lớp 7 ><

BEAR CHỊU

(2x - 1/3)= 2

2x= 2+1/3

2x= 7/3

x= 7/3 : 2

x= 1,66666

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

=>2x=7/3

=>x=7/6

b: Sửa đề: 1/11-5/22

\(\dfrac{8}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)+\dfrac{5}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right)\)

\(=\dfrac{8}{9}:\dfrac{-3}{22}+\dfrac{5}{9}:\dfrac{-9}{15}\)

\(=\dfrac{8}{9}\cdot\dfrac{-22}{3}+\dfrac{5}{9}\cdot\dfrac{-5}{3}\)

\(=\dfrac{-66-25}{27}=\dfrac{-91}{27}\)

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

\(\dfrac{3}{2}\) \(x\) - \(\dfrac{15}{6}\) - \(\dfrac{4}{5}\) = \(x\) + 1

\(\dfrac{3}{2}\)\(x\) - \(x\)          = 1 + \(\dfrac{15}{6}\) + \(\dfrac{4}{5}\)

\(\dfrac{1}{2}\)\(x\)                 =\(\dfrac{43}{10}\)

    \(x\)                 = \(\dfrac{43}{10}\) \(\times\) 2

     \(x\)                = \(\dfrac{43}{5}\)

\(\dfrac{3}{2}\left(x-\dfrac{5}{3}\right)-\dfrac{4}{5}=x+1\\ \Rightarrow\dfrac{3.\left(x-\dfrac{5}{3}\right)}{2}-\dfrac{4}{5}=x+1\\ \Rightarrow\dfrac{3x-5}{2}-\dfrac{4}{5}=x+1\Rightarrow\dfrac{5\left(3x-5\right)}{10}-\dfrac{8}{10}=x+1\\ \Rightarrow\dfrac{15x-33}{10}=x+1\\ \Rightarrow\dfrac{15x-33}{10}-x=x+1\\ \Rightarrow\dfrac{15x-33}{10}=x+1-x\\ \Rightarrow5x-33=10\\ \Rightarrow5x=10+33\\\Rightarrow5x=43\\ \Rightarrow x=\dfrac{43}{5} \)

\(\dfrac{3}{2}\times\left(x-\dfrac{5}{3}\right)-\dfrac{4}{5}=x+1\)

\(\Leftrightarrow\dfrac{3}{2}\times x-\dfrac{5}{2}-\dfrac{4}{5}=x+1\)

\(\Leftrightarrow\dfrac{3}{2}\times x-x=1+\dfrac{5}{2}+\dfrac{4}{5}\)

\(\Leftrightarrow\dfrac{1}{2}\times x=\dfrac{43}{10}\)

\(\Leftrightarrow x=\dfrac{43}{10}\div\dfrac{1}{2}\)

\(\Leftrightarrow x=\dfrac{43}{5}\)

a) \(\dfrac{13}{20}+\dfrac{3}{5}+x=\dfrac{5}{6}\)

\(\Rightarrow\dfrac{5}{4}+x=\dfrac{5}{6}\)

\(\Rightarrow x=\dfrac{5}{6}-\dfrac{5}{4}\)

\(\Rightarrow x=\dfrac{-5}{12}\)

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

\(\Rightarrow x+\dfrac{1}{3}=\dfrac{11}{15}\)

\(\Rightarrow x=\dfrac{11}{15}-\dfrac{1}{3}\)

\(\Rightarrow x=\dfrac{2}{5}\)

c)\(\dfrac{-5}{8}-x=\dfrac{-3}{20}-\dfrac{-1}{6}\)

\(\dfrac{-5}{8}-x=\dfrac{1}{60}\)

\(\Rightarrow x=\dfrac{-5}{8}-\dfrac{1}{60}\)

\(\Rightarrow x=\dfrac{-77}{120}\)

d) \(\dfrac{3}{5}-x=\dfrac{1}{4}+\dfrac{7}{10}\)

\(\Rightarrow\dfrac{3}{5}-x=\dfrac{19}{20}\)

\(\Rightarrow x=\dfrac{3}{5}-\dfrac{19}{20}\)

\(\Rightarrow x=\dfrac{-7}{20}\)

e) \(\dfrac{-3}{7}-x=\dfrac{4}{5}+\dfrac{-2}{3}\)

\(\Rightarrow\dfrac{-3}{7}-x=\dfrac{2}{15}\)

\(\Rightarrow x=\dfrac{-3}{7}-\dfrac{2}{15}\)

\(\Rightarrow x=\dfrac{-59}{105}\)

g) \(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)

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

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

\(\Rightarrow x=\dfrac{-13}{12}\)

3/5 : x = 5/6 - 1/3

3/5 : x = 1/2

x = 3/5 : 1/2

x = 6/5

Cái này lớp 4 mà

3/5 : x = 5/6 - 1/3

3/5 : x = 1/2

x = 3/5 : 1/2

x = 6/5

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

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

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

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

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

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

\(x=\dfrac{3}{10}\)

\(\left(\dfrac{6}{5}-2,4\right):\dfrac{-3}{5}-\dfrac{3}{2}.\left(1\dfrac{1}{2}:\dfrac{1}{2}\right)\)

= \(\dfrac{-6}{5}\): \(\dfrac{-3}{5}-\dfrac{3}{2}.\left(\dfrac{3}{2}:\dfrac{1}{2}\right)\)

= \(\dfrac{-5}{2}\)

\(\left(\dfrac{6}{5}-2,4\right):\left(-3,5\right)-\dfrac{3}{2}.\left(1\dfrac{1}{2}:\dfrac{1}{2}\right)=-\dfrac{6}{5}:\left(-\dfrac{7}{2}\right)-\dfrac{3}{2}.3=\dfrac{12}{35}-3=-\dfrac{93}{35}\)

\(\left(\dfrac{6}{5}-2,4\right):\dfrac{-3}{5}-\dfrac{3}{2}.\left(1\dfrac{1}{2}:\dfrac{1}{2}\right)\) 

=\(\left(\dfrac{6}{5}-\dfrac{12}{5}\right):\dfrac{-3}{5}-\dfrac{3}{2}.\left(\dfrac{3}{2}:\dfrac{1}{2}\right)\) 

=\(\dfrac{-6}{5}:\dfrac{-3}{5}-\dfrac{3}{2}.3\) 

=\(2-\dfrac{9}{2}\) 

=\(\dfrac{-5}{2}\)