问题是这样的设A=2x^2-3xy+y^2-x+2y,B=4x^2-6xy+2y^2-3x-y ,若│x-2a│+(y+

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/12 03:42:02

问题是这样的
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
打不出2次方那些的用"^"来代替也就是说2X^2就是2X的2次方
不只是要答案要的作题的解析

│x-2a│+(y+3)^2=0
必须x-2a=0,y+3=0
即x=2a,y=-3
A=2x^2-3xy+y^2-x+2y
=(2x-y)(x-y)-(x-2y)
B=4x^2-6xy+2y^2-3x-y
=2(2x^2-3xy+y^2)-3x-y
=2(2x-y)(x-y)-3x-y
B-2A=2(2x-y)(x-y)-3x-y-2(2x-y)(x-y)-2(x-2y)
=-3x-y-2(x-2y)
=-3x-y-2x+4y
=3y-x
=-9-2a=a
所以a=-3
x=2a=-6,y=-3
则A=(2x-y)(x-y)-(x-2y)
=(-12+3)(-6+3)-(-6+6)
=9*3
=27

问题是这样的设A=2x^2-3xy+y^2-x+2y,B=4x^2-6xy+2y^2-3x-y ,若│x-2a│+(y+ 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若│ 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若x 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y.若x 设A=2X²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若| 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y 若| 设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若| 1.设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y, 设A=2x²-3xy+y²-x+2y ,B=4x²-6xy+2y²+3x-y . 1.设A=2x²-3xy+y²+x-3y,B=4x²-6xy+2y²+4x-y, 设A=2x²-3xy+y²+x-3y ,B=4x²-6xy+2y²+4x-y , 设A=2x方-3xy+y方-x+2y,B=4x方-6xy+2y方+3x-y.若|x-2a|+（y+3）的平方=0,且B-