1.已知y=2x,求(2x+y/x^2-2xy+y^2)乘以(x-y)的值.2.计算题：a-2b+(4b^2/a+2b)+(4a^2b/a^2-4b^2)

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知x≠y,x^2-x=y^2-y,求x+y的值. 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知2/x+2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知2/x 2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知:x+2y=2011 求代数式{(x^+y^)-(x-y)^+2x(x+y)}/2x的值 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 1.(x-2y)(x+2y)-(x平方+y)(x平方-y) 2.(2x-y)(y+2x)-(2y+x)(2y-x)3.已知：x+y=6,x平方-y平方=48,求x,y的值4.x平方-2x分之x+2 -- x平方-4x+4分之x-1 已知x+y/x=11/8,求x-y/x+2y的值 已知：x(x-50y)+xy=50y^2,求：(x-y):y=? 已知x+y/y=11/8,求x-y/x+2y的值. 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值