已知4x2-4x+1+3y-2=0,求x+y的值.
已知x2-4x-1=0,求代数式(2x-3)2-(x+y)(x-y)-y2的值
已知x2+4x+y2-2y+5=0,求x,y的值.
已知4x2-4x+1+3y-2=0,求x+y的值.
已知[(x2+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,
已知实数x,y满足x2+y2-4x+1=0,求2x+y的取值范围?
已知实数x,y满足x2+y2+4x+3=0,求(y-2)/(x-1)的值域.
已知:x,y为实数,y=根号x2-4+根号4-x2+1除以x-2,求3x+4y的值
已知x+y=5,xy=4,求:(1)(x+y)2;(2)x2+y2;(3)x-y的值.
已知多项式2x2+xy-3y2-x-4y-1=(2x+3y+m)(x-y+n),求m、n的值.
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
已知x+y=4,xy=3求(1)x2=y2 (2)x-y的值
已知2x=y,求代数式[(x2+y2)-(x-y)2+2y(x-y)]÷(4y)的值.