\(A=\left(\sqrt{6\left(x^2-2xy^2+y^3\right)}+\sqrt{6.4x^2y}\right).\frac{1}{\sqrt{6y}}\)
\(=\left(\sqrt{6\left(x^2-xy^2+y^3\right)}+2x\sqrt{6y}\right).\frac{1}{\sqrt{6y}}\)
\(=\left[\sqrt{6}\left(\sqrt{x^2-xy^2+y^3}+2x\sqrt{y}\right)\right].\frac{1}{\sqrt{6y}}=\sqrt{6}\left(\sqrt{x^2-xy^2+y^3}-2x\sqrt{y}\right).\frac{1}{\sqrt{6}\sqrt{y}}\)
\(=\frac{x^2-xy^2+y^3}{\sqrt{y}}-\frac{2x\sqrt{y}}{\sqrt{y}}=\frac{x^2-xy^2+y^3}{\sqrt{y}}-2x\)
mik chỉ lm đến đây đc thui
\(B=\frac{7y\left(y-x\right)\sqrt{7xy}}{2\sqrt{7xy}}=7y^2-7x\)
\(C=\frac{\sqrt{m}}{\sqrt{\left(x-1\right)^2}}.\frac{4m^3\left(x-1\right)^2}{9}=\frac{\sqrt{m}}{\left(x-1\right)}.\frac{4m^3\left(x-1\right)^2}{9}=\frac{4m^3\sqrt{m}\left(x-1\right)}{9}\)