$\frac{1}{2}$`x` `-` $\frac{5}{2}$`=` $\frac{4}{5}$
`⇔`$\frac{1}{2}$`x``=`$\frac{4}{5}$`+`$\frac{5}{2}$
`⇔`$\frac{1}{2}$`x``=`$\frac{33}{10}$
`⇔``x =` $\frac{33}{10}$ : $\frac{1}{2}$
`⇔``x =` $\frac{33}{5}$
$\text{Vậy}$ `x =` $\frac{33}{5}$
$\text{@Star}$