Question

小红用5.5元钱可买两只相同的铅笔和一个笔记本.当文具价格上涨10%后,5.5元恰好能买一支同样的%C

Answer 1

设上涨前一支铅笔x元,则上涨前一个笔记本(5.5-2x)元根据题意得：(1+10%)x+(1+10%)(5.5-2x)=5.51.1x+6.05-2.2x=5.5-1.1x=-0.55x=0.55.5-2x=4.5(元)4.5*(1+10%)*(1+10%)=5.445≈5.45（元）答：这5.5元还够买一个笔记本...