已知x2-4x+2y2-4y+6=0,先化简再求值:(2x+y)(2x-y)-(2x-y)2.
已知x2-4x+2y2-4y+6=0,先化简再求值:(2x+y)(2x-y)-(2x-y)2.
化简求值:已知x、y满足:x2+y2-4x+6y+13=0,求代数式(3x+y)2-3(3x-y)(x+y)-(x-3y
已知:x2+4x+y2-6y+13=0,求(x-2y)/(x²+y²)
先化简再求值:y(x+y)+(x-y)2-x2-2y2,其中x=-13
化简求值:(2x+y)(x-2y)-2x(x+y),其中x、y满足x2+y2-2x+4y=-5.
先化简再求值[(x+y)2-(x+y)(x+3y)-4y2]÷2y,其中x=-2,y=12
已知2x=y,求代数式[(x2+y2)-(x-y)2+2y(x-y)]÷(4y)的值.
.先化简再求值:(2x+y)(2x+y)-(2x-y)平方其中X,Y满足X平方+Y平方-2X+4Y+5=0
已知x2+4x+y2-2y+5=0,求x,y的值.
已知x2+y2-6x+4y+13=0,求2x+3y
先化简再求值:-(x2+y2)+[-3xy-(x2-y2)],其中x=-1,y=2.
已知[(x2+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,