设原来每件利润为X,则调价后每件利润为X-0.4原友做来销量为30000/X,现在销量为30000/X+5000所以(X-0.4)(30000/X+5000)=30000+200030000-12000/X+5000X-2000=320005000X-4000-12000/好银衡X=05X-4-12/X=05X^2-4X-12=0(5X+6)(X-2)=0解得x=2或X=-1.2舍搏带去所以X=2所以调价前每件商品的利润为2元