买两种布料共138m,花了540元,蓝布料每米3元,黑的每米5元,两种各买了几米
问题描述:
买两种布料共138m,花了540元,蓝布料每米3元,黑的每米5元,两种各买了几米
答
设x?
买两种布料共138m,花了540元,蓝布料每米3元,黑的每米5元,两种各买了几米
设x?