Answer :
[tex]f(x)=\frac{3}{x+2}-\sqrt[]{x-3}[/tex]
now you just have to replace the x by 7 and solve
[tex]\begin{gathered} f(7)=\frac{3}{7+2}-\sqrt[]{7-3} \\ f(7)=\frac{3}{9}-\sqrt[]{4} \\ f(7)=0.333-2 \\ f(7)=-1.67 \end{gathered}[/tex]