解方程:2x2-5x+1=0.
∵a=2,b=-5,c=1,
∴b2-4ac=17,
∴x=5±174,
∴x1=5+174,x2=5-174.
用所给词的适当形式填空
小题1:Why all the _________ (smile) faces? .
小题2:We will take __________(turn) to clean our classroom.
小题3:These stories end with ___________(happy)and laughter .
小题4:________ (wear) different colors of clothes can affect our feelings.
小题5:I ______________(not,pass) the English exam,so I was so sad.
公司债的风险不仅与市场资金供需状况相关,还与公司的经营状况直接相关。