if f(x) ax^2+bx+c , g(x) :1/3x^2+2 and fg(x)= 18x^4+24x^2+11/(3x^2+2)^"

2 answers

FIND A, B AND C
The expression ends with (3x^2 + 2)^ and lacks an exponent. Maybe ^" is some special notation?

I assume you mean g(x) = 1/(3x^2 + 2)

and fg(x) means f(x)*g(x) and not f(g(x))

As usual, a little ambiguity delays responses.