2又5/6*(21除以2又2/7-1/6)除以4/9

问题描述:

2又5/6*(21除以2又2/7-1/6)除以4/9

57又65/128

=17/6*(21*7/16-1/6)*9/4
=17/6*9/4*433/48
=51/8*433/48
=57又65/128