7,5x:\(\frac{50}{21}\)=\(\frac{64}{25}\)

7,5x = \(\frac{64}{25}.\frac{50}{21}\)

7,5x = \(\frac{128}{21}\)

x = \(\frac{128}{21}:7,5\)

x = \(\frac{256}{315}\)

256

315

\(7,5x:\left[9-6\frac{13}{21}\right]=2\frac{13}{25}\)

\(\Leftrightarrow7,5x:\left[9-\frac{139}{21}\right]=\frac{63}{25}\)

\(\Leftrightarrow7,5x:\frac{50}{21}=\frac{63}{25}\)

\(\Leftrightarrow7,5x=\frac{63}{25}.\frac{50}{21}\)

\(\Leftrightarrow7,5x=6\)

\(\Leftrightarrow x=6:7,5\)

\(\Leftrightarrow x=\frac{4}{5}=0,8\)

(Chúc bạn học tốt và tíck cho mìk vs nha!)

\(x:(3\frac{1}{2}-5\frac{1}{6})=4\frac{1}{5}-6\frac{2}{3}\)                           b,\((2\frac{1}{3}+3\frac{1}{2})\cdot x=-4\frac{1}{4}+3\frac{1}{7}\)

\(x:\frac{-5}{3}\)=\(\frac{-37}{15}\)                                                              \(\frac{35}{6}\cdot x=\)\(\frac{-31}{28}\)

\(x=\frac{-37}{15}\cdot\frac{-5}{3}\)                                                              \(x=\frac{-31}{28}:\)\(\frac{35}{6}\)

\(x=\frac{37}{9}\)                                                                              \(x=\frac{-93}{490}\)

Vậy x=\(\frac{37}{9}\)                                                                           Vậy x=\(\frac{-93}{490}\)

7,5x:\((9-6\frac{13}{21})=2\frac{13}{25}\)

7,5x:\(\frac{50}{21}\)=\(\frac{63}{25}\)

7,5x=\(\frac{63}{25}:\frac{50}{21}=\frac{1323}{1250}\)

x=\(\frac{1323}{1250}:7,5\)

x=\(\frac{441}{3125}\)

Vậy x=\(\frac{441}{3125}\)

\(a,2\frac{x}{7}=\frac{75}{35}\)

\(\frac{75}{35}=2\frac{5}{35}=2\frac{1}{7}\)

\(\Rightarrow x=1\)

\(b,47:4=...\left(+3\right)\)

     \(\Rightarrow\left(47-3\right):4=11\)

      \(\Rightarrow x=11\)

\(c,\frac{112}{5}=\frac{336}{15}=22\left(+6\right)\)

     \(\Rightarrow x=22\frac{x=6}{15}\)

\(d,7,5x=\frac{75x}{100}:\left(9-6\frac{13}{21}\right)=2\frac{13}{25}\)

     \(\frac{75x}{100}:\left(9-\frac{139}{21}\right)=\frac{63}{25}\)

       \(\frac{75x}{100}:\frac{50}{21}=\frac{63}{25}\)

           \(\Rightarrow\frac{63^3}{25^{\left(1\right)}}\cdot\frac{50^{\left(2\right)}}{21^1}=6=\frac{6}{1}\)

             \(\Rightarrow\frac{6}{1}=\frac{600}{100}\)

Con d sai đề