`8`. `Tìm` `x`
`a)` $\frac{3}{8}$ .`x` `=` $\frac{3}{5}$
`<=>``x` `=` $\frac{3}{5}$ : $\frac{3}{8}$
`<=>` `x` `=`$\frac{3}{5}$ .$\frac{8}{3}$
`<=>` `x` `=` $\frac{8}{5}$
`Vậy` `x` `=` $\frac{8}{5}$
`b)` `x`. $\frac{5}{3}$ =$\frac{11}{3}$
`<=>` `x` `=` $\frac{11}{3}$ : $\frac{5}{3}$
`<=>` `x` `=` $\frac{11}{3}$. $\frac{3}{5}$
`<=>` `x` `=` $\frac{11}{5}$
`Vậy` `x` `=` $\frac{11}{5}$
`c)` `x`: $\frac{7}{4}$ = $\frac{2}{7}$
`<=>` `x` `=` $\frac{2}{7}$ . $\frac{7}{4}$
`<=>` `x` `=` $\frac{2}{4}$
`<=>` `x` `=` $\frac{1}{2}$
`Vậy` `x` `=` $\frac{1}{2}$
`d)` $\frac{3}{5}$ : `x` `=` $\frac{6}{5}$
`<=>``x` ` =` $\frac{3}{5}$ : $\frac{6}{5}$
`<=>` `x` `=`$\frac{3}{5}$ .$\frac{5}{6}$
`<=>` `x` `=` $\frac{3}{6}$
`<=>` `x` `=` $\frac{1}{2}$
`Vậy` `x` `=` $\frac{1}{2}$
