4a^2b / 3cd^2 · 5c^2d / 4ab^2 ÷ 2abc / 3d
=4a^2b / 3cd^2 · 5c^2d / 4ab^2· 3d/ 2abc
=4a^2b*5c^2d*3d/3cd^2*4ab^2*2abc
=5a^2bc^2d^2/2a^2b^3c^2d^2
=5/2b^2昨天晚上才要啊！！呜呜呜~~~~~