题目

       When other nine-year-old kids were playing games, she was working at a petrol station. When other teens were studying or going out, she struggled to find a place to sleep on the street. But she overcame these terrible setbacks to win a highly competitive scholarship（奖学金）and gain entry to Harvard University. And her amazing story has inspired a movie,“Homeless to Harvard: The Liz Murray Story”, shown in late April.        Liz Murray, a 22-year-old American girl, has been writing a real-life story of willpower and determination. Liz grew up in the shadow 某车间加工120个零件后，采用了新工艺，工效是原来的1.5倍，这样加工同样多的零件就少用1小时，采用新工艺前每小时加工多少个零件？若设采用新工艺前每小时加工x个零件，则根据题意可列方程为　　．