对课本上的习题,同学们若能进行多方面的深入思考,往往能收到意想不到的效果.课本原题(义务教育教科书人教版《数学》七年级上册第106页的练习第1题)某商店有两种书包,每个小书包比大书包的进价少10元,而它们的售后利润相同.其中,每个小书包的盈利率为30%,每个大书包的盈利率为20%,试求两种书包的进价.分析:设每个小书包的进价为x元,则每个大书包的进价为(x+10)元.因为每个小 On the textbook exercises, students in many aspects of in-depth thinking, often can receive unexpected results. Textbook original title (compulsory education textbook PEP 7th grade Volume 106 exercise 1 ) There are two kinds of bags in a shop, each with a small purchase price of 10 yuan less than the big bag, and the same profit after sale, of which, the profit rate of each small bag is 30% and the profit rate of each big bag is 20%, try asking price of two bags Analysis: Suppose the purchase price of each small bag is x yuan, the purchase price of each big bag is (x + 10) yuan because each small