Question

1.若x^2+y^2-2x+6y+10=0,则代数式x^2+y^2=____

Answer 1

1.10 2.5 3.4 4.9x^2+12xy+4y^2=(3x+2y)^2 4x^2+12xy+9y^2=(2x+3y)^2 36x^2+12xy+y^2=(9x+y)^2 5.(1)x^n-1 (2) （x+1)(x^n+x^n-1+x^n-2+...+x^2+X+1)=x^n-1＝（x+1)*0=0=x^2012-1=0　 x^2012=1 6.A 7.18