Question

Tìm x biết:

A) \(0,5x-\frac{2}{3}x=\frac{7}{12}\)                                                     B)\(x:4\frac{1}{3}=-2,5\)

C)\(5,5x=\frac{13}{15}\)                                                                  D)\(\left[\frac{3x}{7}+1\right]:\left(-4\right)=\frac{-1}{28}\)

Answer 1

A)X.(0,5-2/3)=7/12

X.(-1/6)=7/12

X=7/12chia(-1/6)

X=11/3

B)X=-2,5.4/1/3=-26/15

C)X=13/15chia 5,5=26/165

D)X=[3x/7+1]=(-1)/28.(-4)

X=[3x/7+1]=1/112

X=1/112-1

X=-111/112

X=-111/112.3x/7

X=-333/784

Answer 2

a) \(0,5x-\frac{2}{3}x=\frac{7}{12}\)

    \(-\frac{1}{6}x=\frac{7}{12}\)

   \(x=\frac{7}{12}:\left(-\frac{1}{6}\right)\)

   \(x=-\frac{7}{2}\)

b) \(x:4\frac{1}{3}=-2,5\)

    \(x=-2,5\)x    \(4\frac{1}{3}\)

    \(x=-\frac{65}{6}\)

c) \(5,5x=\frac{13}{15}\)

     \(x=\frac{13}{15}:5,5\)

   \(x=\frac{26}{165}\)

d)\(\left[\frac{3x}{7}+1\right]:\left(-4\right)=\frac{-1}{28}\)

\(\frac{3x}{7}+1=\left(\frac{-1}{28}\right)\)x\(\left(-4\right)\)

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

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

\(3x:7=-\frac{6}{7}\)

\(3x=\left(-\frac{6}{7}\right)\)x   \(7\)

\(3x=-6\)

\(x=-2\)