(20%+20%+120)*2+100=x 要详解
问题描述：
(20%+20%+120)*2+100=x 要详解
(20%x+20%x+120)*2+100=x
答
=>(40%x+120)*2+100=x
=>80%x+240+100=x
=>340=20%x
=>x=340/20%
=>x=1700