Y-X=45 (80%Y-X)×8=(Y-35-X)×12

Y-X=45 (80%Y-X)×8=(Y-35-X)×12 Y-X=45 (85%Y-X)×8=(Y-35-X)×12 (x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) x+80%y=42 y-x=12 [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 （x+2y)(x-2y)-(2y-x)(-2x-y)其中x=8,y=-8 已知实数x,y满足|x|+x+y=10、x+|y|-y=12,则x+y的值? X.Y为自然数,X(X-Y)-Y(Y-X)=12,求X.Y的值 x,y都是自然数,且x(x-y)-y(y-x)=12,求x+y-xy的值 [(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x=