Question

\(\dfrac{\sqrt{45mn^2}}{\sqrt{20m}}vớim>0,n>0\)

Answer 1

\(=\sqrt{\dfrac{\dfrac{9}{4}mn^2}{m}}=\dfrac{3}{2}\cdot n\)

Answer 2

=\(\dfrac{3n}{2}\)

Answer 3

\(\dfrac{\sqrt{45mn^2}}{\sqrt{20m}}\left(m,n>0\right)\\ =\sqrt{\dfrac{45mn^2}{20m}}=\sqrt{\dfrac{5m.9n^2}{5m.4}}\\ =\sqrt{\dfrac{9n^2}{4}}=\sqrt{\left(\dfrac{3n}{2}\right)^2}=\left|\dfrac{3n}{2}\right|\)

\(=\dfrac{3n}{2}\) \((Vì: n>0=>3n/2>0)\)