Question 978321
A and B are in relation to each other.  Solution elements A and B are infinite.


{{{3AB(1/3)=3AB (1/A)+3AB(1/B)}}}
{{{AB=3B+3A}}}
{{{AB-3B=3A}}}
{{{B(A-3)=3A}}}
{{{highlight_green(B=(3A)/(A-3))}}}


You can find some whole numbered pairs of A and B.  Be sure {{{A<>3}}}.

A=6 is one example which should work.
Try 9 also for A, and see if that works.



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You reported A=4 and B=12.
B=(3A)/(A-3)
{{{12=(3*4)/(4-3)}}}
{{{12=12/1}}}
{{{12=12}}}
Yes, that combination works.  This is not the only combination that will work.  You can find others.