Composing two functions means to use the output of one as the input of the others. In fact, you can write the composition as
[tex] (f \circ g)(x) = f(g(x)) [/tex]
and then compute both functions, from inside outwards:
[tex] f(g(x)) = f(x+2) = 2(x+2)^2 + (x+2) - 3 [/tex]
And maybe it's a good idea to simplify the expression: expand the square to get
[tex] 2x^2+8x+8 + x+2 - 3 [/tex]
sum like terms:
[tex] 2x^2+9x+7 [/tex]
