The given expression is
[tex]\frac{4}{5}+(-\frac{2}{5})-\frac{1}{5}[/tex]Notice that all the fractions have the same denominator, which means they are homogeneous fractions. We just have to solve the numerators because the denominator will be the same.
[tex]\frac{4-2-1}{5}=\frac{1}{5}[/tex]