已知2x=y,求代数式[(x2+y2)-(x-y)2+2y(x-y)]÷(4y)的值.
已知2x=y,求代数式[(x2+y2)-(x-y)2+2y(x-y)]÷(4y)的值.
已知 x2+xy=12,xy+y2=15,求代数式(x+y)2-2y(x+y)的值.
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+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,
已知2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值?
已知x2+y2=20,x2+xy-2y2=2(x+2y),求x+y的值
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
已知y+2x=1,求代数式(y+1)2-(y2-4x)的值.
已知x(x+1)-(x2-y)=-3,求代数式[(x-2y)2+(x-2y)(x+2y)-2x(2x-y)]÷2x的值.
已知x2-4x-1=0,求代数式(2x-3)2-(x+y)(x-y)-y2的值
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
当x=-1,y=-2时,求代数式[2x2-(x+y)(x-y)][(-x-y)(-x+y)+2y2]的值.