买2瓶白酒,12瓶啤酒共付42元,已知一瓶白酒与8瓶啤酒的价钱相等,每瓶白酒和啤酒各多少元,

问题描述:

买2瓶白酒,12瓶啤酒共付42元,已知一瓶白酒与8瓶啤酒的价钱相等,每瓶白酒和啤酒各多少元,

设白酒X元,啤酒Y元 X=8Y 12Y+2X=42 得X=12 Y=1.5