Question 164402
Remember GoF is shorthand notation for g(f(x))



{{{g(x)=x^2-2x+3}}} Start with the given function



{{{g(f(x))=(2x+3)^2-2(2x+3)+3}}} Plug in {{{f(x)=2x+3}}}



{{{g(f(x))=(4x^2+12x+9)-2(2x+3)+3}}} FOIL



{{{g(f(x))=4x^2+12x+9-4x-6+3}}} Distribute



{{{g(f(x))=4x^2+8x+6}}} Combine like terms.



So GoF is {{{g(f(x))=4x^2+8x+6}}}