(1)y+2y=45(2)x-360=312
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
化简求值:【(x+Y)(X-Y)-(X-Y)的平方+2Y(2-Y)】除4Y,其中X=1 Y=2
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知4x=9y求(1)x+y/y (2)y-x/2x
集合N={(x,y)|(x-1)^2}+(y-1)^20},M={(x,y)|x^2+y^2
(1)正数x,y满足x^2-y^2=2xy,求(x-y)/(x+y)