Question 596955
{{{f(x)=x^2+3x+2}}}



{{{f(2u)=(2u)^2+3(2u)+2}}}



{{{f(2u)=4u^2+3(2u)+2}}}



{{{f(2u)=4u^2+6u+2}}}



So the answer is {{{f(2u)=4u^2+6u+2}}}