Question

Bài 1: tìm x:

a)\(\frac{2}{3}\).x-\(\frac{3}{2}\).x=\(\frac{5}{12}\)

b) \(\frac{7}{9}\):(2+\(\frac{3}{4}\).x)+\(\frac{5}{9}\)=\(\frac{23}{27}\)

c)\(\frac{2}{5}\)+\(\frac{3}{5}\).(3x-3,7)= -\(\frac{53}{10}\)

Answer 1

a) \(x.\left(\frac{2}{3}-\frac{3}{2}\right)=\frac{5}{12}\)

\(\Leftrightarrow x.\left(-\frac{5}{6}\right)=\frac{5}{12}\)

\(\Leftrightarrow x=-\frac{1}{2}\)

b) \(\frac{7}{9}:\left(2+\frac{3}{4}x\right)=\frac{8}{27}\)

\(\Leftrightarrow2+\frac{3}{4}x=\frac{21}{8}\)

\(\Leftrightarrow\frac{3}{4}x=\frac{5}{8}\)

\(\Leftrightarrow x=\frac{5}{6}\)

c) \(\frac{3}{5}.\left(3x-3,7\right)=-\frac{57}{10}\)

\(\Leftrightarrow3x-3,7=-\frac{19}{2}\)

\(\Leftrightarrow3x=-\frac{29}{5}\)

\(\Leftrightarrow x=-\frac{29}{15}\)

Answer 2

Answer 3

mình ko ghi đề đâu

a) \(\Rightarrow\left(\frac{2}{3}-\frac{3}{2}\right).x=\frac{5}{12}\)

\(\Rightarrow-\frac{5}{6}.x=\frac{5}{12}\)

\(\Rightarrow x=\frac{5}{12}:\left(-\frac{5}{6}\right)=-\frac{1}{2}\)

b) \(\Rightarrow\frac{7}{9}:\left(2+\frac{3}{4}.x\right)=\frac{8}{27}\)

\(\Rightarrow2+\frac{3}{4}.x=\frac{21}{8}\)

\(\Rightarrow\frac{3}{4}.x=\frac{5}{8}\)

\(\Rightarrow x=\frac{5}{6}\)

c) \(\Rightarrow\frac{3}{5}.\left(3x-3,7\right)=-\frac{53}{10}\)

\(\Rightarrow3x-\frac{37}{10}=-\frac{53}{6}\)

\(\Rightarrow3x=-\frac{77}{15}\)

\(\Rightarrow x=-\frac{77}{45}\)

Answer 4

a) pt<=>\(\frac{2x}{3}-\frac{3x}{2}=\frac{5}{12}\)<=> \(\frac{4x-9x}{6}=\frac{5}{12}\)<=>\(-\frac{10x}{12}=\frac{5}{12}\)<=> x=\(-\frac{5}{10}=-\frac{1}{2}\)

b) pt<=> \(\frac{7}{9}:\left(\frac{8+3x}{4}\right)=\frac{23}{27}-\frac{5}{9}\)

<-=> \(\frac{7}{9}.\frac{4}{8+3x}=\frac{8}{27}\)<=> \(\frac{28}{72+27x}=\frac{8}{27}\)

<=> 8.(72+27x)=28.27

<=> x=\(\frac{\frac{28.27}{8}-72}{27}=-\frac{521}{64}\)

c) 3x-3,7=\(\frac{-19}{2}\)

<=> x=\(\frac{-29}{15}\)

Answer 5

Answer 6

a)\(\frac{2}{3}\cdot x-\frac{3}{2}\cdot x=\frac{5}{12}\)

\(\left(\frac{2}{3}-\frac{3}{2}\right)\cdot x=\frac{5}{12}\)

\(-\frac{5}{6}\cdot x=\frac{5}{12}\)

\(x=\frac{\frac{5}{12}}{-\frac{5}{6}}\)

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

b) \(\frac{7}{9}:\left(2+\frac{3}{4}\cdot x\right)+\frac{5}{9}=\frac{23}{27}\)

\(\frac{7}{9}:\left(2+\frac{3}{4}\cdot x\right)=\frac{23}{27}-\frac{5}{9}\)

\(\frac{7}{9}:\left(2+\frac{3}{4}\cdot x\right)=\frac{8}{27}\)

\(2+\frac{3}{4}\cdot x=\frac{7}{9}:\frac{8}{27}\)

\(2+\frac{3}{4}\cdot x=2\frac{5}{8}\)

\(\frac{3}{4}\cdot x=2\frac{5}{8}-2\)

\(\frac{3}{4}\cdot x=\frac{5}{8}\)

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

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

c) \(\frac{2}{5}+\frac{3}{5}\cdot\left(3x-3.7\right)=-\frac{53}{10}\)

\(\frac{3}{5}\cdot\left(3x-3.7\right)=-\frac{53}{10}-\frac{2}{5}\)

\(\frac{3}{5}\cdot\left(3x-3.7\right)=-5\frac{7}{10}\)

\(3x-3.7=-5\frac{7}{10}:\frac{3}{5}\)

\(3x-3.7=-9\frac{1}{2}\)

\(3x=-9\frac{1}{2}+3.7\)

\(3x=-5.8\)

\(x=\left(-5.8\right):3=-1,9\left(3\right)\)

 

Answer 7

mình nhầm chút nhé

Answer 8

ko nhầm đâu. Mình làm chuẩn rồi đó bạn