Let's write out the term given,
[tex]\sqrt[]{9xy}\text{ }\cdot\sqrt[]{25x}[/tex]Let us find the solution to the term,
[tex]\begin{gathered} \sqrt[]{9xy}\text{ }\cdot\sqrt[]{25x}\text{ = }\sqrt[]{9xy(25)x} \\ =\sqrt[]{9(25)(x\cdot x)(y)} \end{gathered}[/tex][tex]\begin{gathered} =\sqrt[]{(9\times25)(x^1\cdot x^1)(y)} \\ =\sqrt[]{(225)x^{1+1}(y)}\text{ = }\sqrt[]{(225)x^2y} \end{gathered}[/tex]