a) \(0,5x-\dfrac{2}{3}x=\dfrac{7}{12}\)
\(\dfrac{1}{2}x-\dfrac{2}{3}x=\dfrac{7}{12}\)
\(\left(\dfrac{1}{2}-\dfrac{2}{3}\right)x=\dfrac{7}{12}\)
\(\dfrac{-1}{6}x=\dfrac{7}{12}\)
\(x=\dfrac{7}{12}:\dfrac{-1}{6}\)
\(x=\dfrac{-7}{2}\)
b) \(x:4\dfrac{1}{3}=-2,5\)
\(x:\dfrac{13}{3}=\dfrac{-5}{2}\)
\(x=\dfrac{13}{3}.\dfrac{-5}{2}\)
\(x=\dfrac{-65}{6}\)
c) \(5,5x=\dfrac{13}{15}\)
\(\dfrac{11}{2}x=\dfrac{13}{15}\)
\(x=\dfrac{13}{15}:\dfrac{11}{2}\)
\(x=\dfrac{26}{165}\)
d) \(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)
\(\left(\dfrac{3x}{7}+1\right)=\dfrac{-1}{28}.\left(-4\right)\)
\(\dfrac{3x}{7}+1=\dfrac{1}{7}\)
\(\dfrac{3x}{7}=\dfrac{1}{7}-1\)
\(\dfrac{3x}{7}=\dfrac{-6}{7}\)
\(\Rightarrow3x=-6\\ x=\left(-6\right):3\\ x=-2\)
câu d mình nhầm bạn nha
d)\(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)
\(\dfrac{3x}{7}+1=\dfrac{-1}{28}.\left(-4\right)\)
\(\left(\dfrac{3x}{7}+1\right)=\dfrac{1}{7}\)
\(\dfrac{3x}{7}=\dfrac{1}{7}-1\)
\(\dfrac{3x}{7}=\dfrac{-6}{7}\)
Ta có : 3x =-6
x = -6:3
x=-2
a) 0,5x-\(\dfrac{2}{3}x=\dfrac{7}{12}\)
x\(\left(\dfrac{1}{2}-\dfrac{2}{3}\right)=\dfrac{7}{12}\)
\(\dfrac{-1}{6}x=\dfrac{7}{12}\)
x = \(\dfrac{7}{12}:\dfrac{-1}{6}\)
x =\(\dfrac{-7}{2}\)
b)\(x:4\dfrac{1}{3}=-2,5\)
\(x:\dfrac{13}{3}=\dfrac{-25}{10}\)
\(x=\dfrac{-5}{2}:\dfrac{13}{3}\)
\(x=\dfrac{-15}{26}\)
c)5,5\(x\)=\(\dfrac{13}{15}\)
\(\dfrac{11}{2}\)\(x\)=\(\dfrac{13}{15}\)
\(x=\dfrac{13}{15}:\dfrac{11}{2}\)
\(x=\dfrac{26}{165}\)
d)\(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)
\(\dfrac{3x}{7}+1\)=\(\dfrac{-1}{28}:\left(-4\right)\)
\(\left(\dfrac{3x}{7}+1\right)=\dfrac{1}{112}\)
\(\dfrac{3x}{7}=\dfrac{1}{112}-1\)
\(\dfrac{3x}{7}=\dfrac{-111}{112}\)
ta có 3x.112=-111.7
3x.112=-777
Vì -777 \(⋮̸̸\)112
\(\Rightarrow\) Bài sai
