12b^3c^6/(3bc^3)^2 сократите дробь

=12b^3c^6/9b^2c^6=4b/3

12b^3c^6/(3bc^3)^21)(3bc^3)^2=9b^2c^612b^3c^6/9b^2c^6=3b^2c^6×4b/3b^2c^6×3=4b/3 ______. ______