设A=2x^2-3xy+y^2-x+2y,B=4x^2-6xy+2y^2+3x-y.若/x-2a/+(y+3)^2=0,且B-2A=a,求A的值
问题描述：
设A=2x^2-3xy+y^2-x+2y,B=4x^2-6xy+2y^2+3x-y.若/x-2a/+(y+3)^2=0,且B-2A=a,求A的值
写的详细一点,对了,答案上写的最终A应该等于283,谢谢您的帮助,我非常需要,希望您可以快一点!
答
|x-2a|+(y+3)^2=0x=2a,y=-3B-2A=aa=4x^2-6xy+2y^2-3x-y-2(2x^2-3xy+y^2-x+2y)=4x^2-6xy+2y^2-3x-y-4x^2+6xy-2y^2+2x-4y=-x-5y|x-2a|=|x-2(-x-5y)|=|x+2x+10y|=|3x+10y|=|3x-30|=0解得x=10A=2x^2-3xy+y^2-x+2y=(x-y)(...