2(x-1)(x-9)=2x²-20x+18
2(x-2)(x-4)=2x²-12x+16
设原式为2(x-a)(x-b)=2x²-2(a+b)x+2ab.
2ab=18,ab=9
2(a+b)=12,a+b=6
a=b=3,原式为2(x-3)²虽然我最后还是看不懂，不过还是谢谢你了不客气