x²+y²-10x-6y+34=0可化为(x-5)²+(y-3)²=0所以x-5=0,y-3=0即x=5,y=32x²-2y²分之4x²-8xy+4y²=2(x+y)(x-y)分之4(x-y)²=(x+y)分之2（x-y)=(5+3)分之2（5-3）=8分之4=2分之...