x1+x2=1-2a,x1x2=a方(x1+2)(x2+2)=x1x2+2(x1+x2)+4=a方+2-4a+4=11所以(a-2)方=9,a=5或-1
x1+x2=1-2a,x1*x2=a*a所以原式=a*a+2*(1-2a)+4=11,a=-1或5