Answer
$26$
Work Step by Step
$(f+g)(x)=f(x)+g(x)$
$(f+g)(x)=f(x)+g(x)=x^2+4x+x+2=x^2+5x+2$
Plug in $x=3$ into $(f+g)(x)$: $(f+g)(3)=(3)^2+5(3)+2=9+15+2=26$
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