Viết sai 1 số ;v, and I think là Max =))
\(A=\dfrac{bc\sqrt{a-1}+ac\sqrt{b-4}+ab\sqrt{c-9}}{abc}\)
\(=\dfrac{bc\sqrt{1\left(a-1\right)}+\dfrac{ac\sqrt{4\left(b-4\right)}}{2}+\dfrac{ab\sqrt{9\left(c-9\right)}}{3}}{abc}\)
\(\le\dfrac{\dfrac{abc}{2}+\dfrac{abc}{4}+\dfrac{abc}{6}}{abc}=\dfrac{1}{2}+\dfrac{1}{1}+\dfrac{1}{6}=\dfrac{11}{12}\)
Vậy GTLN là.....