x^2-6x+9=0(x-3)^2=0x^2-6x+q=2x^2-6x=2-qx^2-6x+9=2-q+9(x-3)^2=11-q
x^2-6x+16=7则x^2-6x+16+Q-16=(x-p)^2+Q-16=7(x-P)^2=23-Q
