x^+y^-6x-8y+25=0.求xy

问题描述:

x^+y^-6x-8y+25=0.求xy

x²+y²-6x-8y+25=0
x²-6x+9+y²-8y+16=0
(x-3)²+(y-4)²=0
x-3=0 x=3
y-4=0 y=4
xy=3×4=12