Answer :

[tex]0.2=\frac{2}{10} \\\\ 2.8=2\frac{8}{10}=\frac{28}{10} \\\\ 2x^{(10}-\frac{2}{10}(4-x)=\frac{28}{10} \\\\ 20x-2(4-x)=28 \\\\ 20x-8+x=28 \\\\ 21x=28+8 \\\\ 21x=36 \\\\ \boxed{x=\frac{36}{21}=\frac{12}{7}}[/tex]