已知 x的二次-4x+y的二次-10y+29=0,求x二次+2xy+y二次的值.谢
问题描述:
已知 x的二次-4x+y的二次-10y+29=0,求x二次+2xy+y二次的值.谢
答
x^2-4x+y^2-10y+29=0
x^2-4x+4+(y-10y+25)=0
(x-2)^2+(y-5)^2=0
x-2=0 x=2
y-5=0 y=5
x^2+2xy+y^2=(x+y)^2=(2+5)^2=7^2=49