Composition of functions:
[tex](g\circ f)(x)=g(f(x))[/tex][tex](g\circ f)(x)=6(x^2+5)-15[/tex][tex]\begin{gathered} (g\circ f)(x)=6x^2+30-15 \\ (g\circ f)(x)=6x^2+15 \end{gathered}[/tex]Evaluate to x=2:
[tex]\begin{gathered} (g\circ f)(2)=6(2)^2+15 \\ (g\circ f)(2)=6\cdot4+15 \\ (g\circ f)(2)=24+15 \\ (g\circ f)(2)=39 \end{gathered}[/tex]Then, (g•f)(2) is:
[tex](g\circ f)(2)=39[/tex]