Answer :

[tex]\dfrac{1}{5}+20.4-\left(-5 \dfrac{3}{5}\right)=\\ \dfrac{1}{5}+20\dfrac{4}{10}-\left(-\dfrac{28}{5}\right)=\\ \dfrac{1}{5}+20\dfrac{2}{5}+\dfrac{28}{5}=\\ \dfrac{29}{5}+\dfrac{102}{5}=\\ \dfrac{131}{5}=26\dfrac{1}{5} [/tex]