Since the function f is defined with the rule:
[tex]f(x)=3x-5[/tex]To find f(g(x)), replace x by g(x):
[tex]f(g(x))=3\cdot g(x)-5[/tex]Since g(x)=2x^2-5, substitute g(x) for its expression:
[tex]\begin{gathered} 3\cdot g(x)-5=3\cdot(2x^2-5)-5 \\ =3\cdot2x^2-3\cdot5-5 \\ =6x^2-15-5 \\ =6x^2-20 \end{gathered}[/tex]Therefore:
[tex]f(g(x))=6x^2-20[/tex]