Answer :
Given:
[tex]\begin{gathered} f(x)=3x^{-1} \\ g(x)=2x-7 \end{gathered}[/tex]Sol:.
[tex]f(g(x))[/tex][tex]\begin{gathered} f(x)=3x^{-1} \\ g(x)=2x-7 \\ f(g(x))=3(2x-7)^{-1} \\ =\frac{3}{2x-7} \end{gathered}[/tex]Domain of function:
[tex]\begin{gathered} =\frac{3}{2x-7} \\ 2x-7\ne0 \\ 2x\ne7 \\ x\ne\frac{7}{2} \end{gathered}[/tex]Domain of function:
[tex]\text{Domain}=\mleft\lbrace x\in R\colon x\ne\frac{7}{2}\mright\rbrace[/tex]