Ta có

a/ 1/3x - 3/4x = 5/12                         1/4x + 3/4 +x =7/8

x(1/3-3/4)=5/12                                   2x=7/8

-5/12x=5/12                                            x=7/8 : 2 =7/16

x=5/12 : -5/12

x=-1

a) \(\frac{2}{3}x-\frac{1}{2}x=\frac{5}{12}\)

\(x\left(\frac{2}{3}-\frac{1}{2}\right)=\frac{5}{12}\)

\(x\left(\frac{4}{6}-\frac{3}{6}\right)=\frac{5}{12}\)

\(\frac{1}{6}x=\frac{5}{12}\)

\(x=\frac{5}{12}:\frac{1}{6}=\frac{5}{2}\)

b) \(25\%x+\frac{3}{4}x+x=\frac{7}{8}\)

\(x\left(25\%+\frac{3}{4}+1\right)=\frac{7}{8}\)

\(x\left(\frac{1}{4}+\frac{3}{4}+1\right)=\frac{7}{8}\)

\(x\left(1+1\right)=\frac{7}{8}\)

\(2x=\frac{7}{8}\)

\(x=\frac{7}{8}:2=\frac{7}{16}\)

Ta có:

a)\(\frac{2}{3}x-\frac{1}{2}x=\frac{5}{12}\)

\(\left(\frac{2}{3}-\frac{1}{2}\right)x=\frac{5}{12}\)

\(\left(\frac{4}{6}-\frac{3}{6}\right)x=\frac{5}{12}\)

\(\frac{1}{6}x=\frac{5}{12}\)

\(x=\frac{5}{12}:\frac{1}{6}\)

\(x=\frac{5}{2}\)

b)  \(25\%.x+\frac{3}{4}x+x=\frac{7}{8}\)

      \(\left(25\%+\frac{3}{4}+1\right)x=\frac{7}{8}\)

     \(\left(\frac{1}{4}+\frac{3}{4}+1\right)x=\frac{7}{8}\)

        \(2x=\frac{7}{8}\)

       \(x=\frac{7}{8}:2\)

       \(x=\frac{7}{16}\)

3/4 - (x - 3) × 2 = 3 1/3 + 2

3/4 - (x - 3) × 2 = 10/3 + 2

3/4 - (x - 3) × 2 = 16/3

(x - 3) × 2 = 3/4 - 16/3

(x - 3) × 2 = -55/12 (lớp 5 chưa học số âm)

Em xem lại đề nhé

\(\frac{3}{4}\times x+\frac{5}{3}\times x=\frac{7}{12}\)

\(\left(\frac{3}{4}+\frac{5}{3}\right)\times x=\frac{7}{12}\)

\(\frac{29}{12}\times x=\frac{7}{12}\)

\(x=\frac{7}{12}\div\frac{29}{12}\)

\(x=\frac{7}{29}\)

-11

 7

\(\frac{\frac{3}{4}-\frac{5}{3}}{x}=\frac{7}{12}\Rightarrow x=\left(\frac{3}{4}-\frac{5}{3}\right):\frac{7}{12}=-\frac{11}{12}:\frac{7}{12}=-\frac{11}{12}.\frac{12}{7}=-\frac{11}{7}\)

X x 2/7 - 2/3 = 1/2

X x 2/7 = 1/2 + 2/3

X x 2/7 = 7/6

X = 7/6 : 2/7

X = 49/12

\(\dfrac{5}{3}\times x-\dfrac{2}{3}=\dfrac{1}{5}\\ \Leftrightarrow\dfrac{5}{3}x=\dfrac{1}{5}+\dfrac{2}{3}\\ \Leftrightarrow\dfrac{5}{3}x=\dfrac{3+10}{15}\\ \Leftrightarrow\dfrac{5}{3}x=\dfrac{13}{15}\\ \Rightarrow x=\dfrac{13}{15}:\dfrac{5}{3}=\dfrac{13}{25}\)

35/6+x=3/4x51/2

35/6+x=153/8

         x=153/8-35/6

          x=319/24

\(\frac{35}{6}+X=\frac{3}{4}\times5\frac{1}{2}\)

 \(\frac{35}{6}_{ }+X=\frac{33}{8}\)

              \(X=\frac{33}{8}-\frac{35}{6}\)

             \(X=\frac{-41}{24}\)

một trăm linh hai phần ba lăm

\(\left(3\dfrac{1}{2}-2x\right)\cdot3\dfrac{1}{3}=7\dfrac{1}{3}\)

\(\Leftrightarrow-2x+\dfrac{7}{2}=\dfrac{22}{3}:\dfrac{10}{3}=\dfrac{11}{5}\)

=>-2x=-13/10

hay x=13/20