1000x-10x2=100010x2-1000x+1000=0x2-100x+100=0x2-100x+502-502+100=0（x-50）2-2400=0（x-50）2=2400x-50=±√2400=±20√6∴x=50±20√6即x1=50+20√6,x2=50-20√6