Respuesta :

[tex]\begin{gathered} f(x)=3x-x+5.2 \\ So, \\ f(-3)=3\times(-3)-(-3)+5.2=-0.8 \\ f\mleft(4\mright)=3\times4-4+5.2=13.2 \\ f(-3)-f(4)=-0.8-13.2=-14 \end{gathered}[/tex]