4.5两题,有答必采4.5两题,有答必采
4.5两题,有答必采4.(x-1)^2+a(x-1)+b=x^2-2x+1+ax-a+b=x^2-2x+ax+1-a+b所以-2x+ax=3x 1-a+b=2-2+a=3 1-5+b=2a=5 b=6所以a+b=11