若2012x+2013y=2011 2013x+2012y=2014,求(x+y)²+(x-y)³的
若x-y=1,求代数式x(x-y)+y(y-x)+2013的值
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
已知x、y满足方程组3x+y=2013,x+3y=2012,求x-y
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
当x=2013,y=2014时,代数式(x/y-y/x)÷x-y/x的值为
已知:x+2y=2011 求代数式{(x^+y^)-(x-y)^+2x(x+y)}/2x的值
已知x²-x=7,y²-y=7,若x≠y,求x+y的值
若正数x,y满足x²-y²=2xy,求(x-y)/(x+y)的值
已知x,y都是实数,且y=根号x-2014+根号2014-x+2013,求x+y的值
已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)