{2x%=y%=1.5,x/2+y/7=30 就今晚

已知x,y 为任意有理数,若M+x²+y²,N=2xy 则N M 大小关系是怎么样的 求过程 今晚就 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) y'-2y=(e^x)-x y'+2y/x=x通解 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 数学题已知p=x^/x-y-y^/x-y,q=(x+y)^-2Y(X+Y), 化简:【(x-y)的2次方+(x+y)(x-y)】除以2x,其中x=3,y=1.5 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y