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if f(x)= 3x lnx, then f ' (x)=?

i used

f' ' (x)=3x(D lnx) + D (3x) (lnx)

f ' '(x)=3x (1/x) + 3 (lnx)

so... f ' '(x)=3+3lnx or 3(1+lnx).

unfortunately this isn't one of the possible answers given. could one of you kind folks help me understand where i went wrong?

thank you

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