Answer:
[tex]x^{15}.y^{9}[/tex]
Step-by-step explanation:
[tex]\frac{x^{19} . y^{21}}{(x^2. y^6)^2} \\\\Here\,\, exponent\,\, rules\,\, will\,\, be\,\, used.\\First\,\, multiply\,\, power\,\, of \,\,2\,\, with\,\, denominator \,\,exponents\\\\\frac{x^{19} . y^{21}}{x^4. y^{12}}\\If \,\, same\,\, bases\,\, are\,\, divided\,\, then\,\, their\,\, exponents\,\, are \,\,subtracted\,\,\\\\x^{19-4}.y^{21-12}\\\\x^{15}.y^{9}[/tex]