Answer:
[tex]\frac{1}{(x^{21})(y^{12}) }[/tex]
Step-by-step explanation:
[tex](\frac{(x^{-3})(y^{2}) }{(x^{4})(y^6) } )^{3} \\\\\frac{(x^{-9})(y^{6}) }{(x^{12})(y^{18}) } \\\\\frac{1}{(x^{21})(y^{12}) }[/tex]
