Answer :
Given functions are:
[tex]\begin{gathered} f\mleft(x\mright)=2x+3 \\ g\mleft(x\mright)=x+1 \end{gathered}[/tex]First find g[f(x)]:
[tex]\begin{gathered} g\lbrack f(x)\rbrack=(2x+3)+1 \\ g\lbrack f(x)\rbrack=2x+4 \end{gathered}[/tex]Nut put x=3 in above equation:
[tex]\begin{gathered} g\lbrack f(3)\rbrack=2(3)+4 \\ g\lbrack f(3)\rbrack=6+4 \\ g\lbrack f(3)\rbrack=10 \end{gathered}[/tex]