-3(2x^2-xy)-4(-6+xy+x^2)其中x,y满足(x+2)^2+丨y-3丨=0
问题描述：
-3(2x^2-xy)-4(-6+xy+x^2)其中x,y满足(x+2)^2+丨y-3丨=0
答
(x+2)^2+丨y-3丨=0
而(x+2)^2>=0,丨y-3丨>=0
∴丨y-3丨=0,(x+2)^2=0
y=3,x=-2
-3(2x^2-xy)-4(-6+xy+x^2)
=-6x^2+3xy+24-4xy-4x^2
=-10x^2-xy+24
=-10*(-2)^2-3*(-2)+24
=-10