已知x²+y²+13-4x+6y=0,求（2x-y)²-2(2x-y)(x+2y)+(x+

来源：学生作业帮编辑：百度作业网作业帮分类：数学作业时间：2024/04/30 08:42:44

已知x²+y²+13-4x+6y=0,求（2x-y)²-2(2x-y)(x+2y)+(x+2y)²的值

x²+y²+13-4x+6y=0
(x²-4x+4)+(y²+6y+9)=0
(x-2)²+(y+3)²=0
平方项恒非负,两非负项之和=0,两非负项分别=0
x-2=0 x=2
y+3=0 y=-3
(2x-y)²-2(2x-y)(x+2y)+(x+2y)²
=[(2x-y)-(x+2y)]²
=(x-3y)²
=[2-3·(-3)]²
=11²
=121

已知x²+y²+13-4x+6y=0,求（2x-y)²-2(2x-y)(x+2y)+(x+ 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 已知x²+y²-2x+4y+5=0,求x+y 已知x²+4x+y-2y+5=0求x+2y 已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x. 已知x²+4x+y²+6y+13=0,求x-y+(2y²/x+y) 请在10；20分前回答已知x²+y²+5=2x+4y,求代数式（2x²-（x+y)(x-y))x((x+y-1) 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 若|x+2y-1|+y²+4y+4=0,求（2x-y）²-2（2x-y)(x+2y)+(x+2y)& 已知x² +y²+5/4=2x+y,求y-x的值已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值