if 2/3 is 1/2 of 4/5 of a certain number, then that number is:

问题描述:

if 2/3 is 1/2 of 4/5 of a certain number, then that number is:
怎么列式啊

设a certain number是x,那么它的4/5的1/2就为x*4/5*1/2=2/3
解得x=5/3