x+y=4,xy=－12,求x^+y^,x^-xy+y^实际求：x平方＋y平方和x平方－xy＋y平方

x+y=4,xy=－12,求x^+y^,x^-xy+y^实际求：x平方＋y平方和x平方－xy＋y平方 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? x+y=12 xy=9 求x y 若x+y=4,x^3+y^3=(x+y)(x^2-xy+y^2)z,求x^3+12xy+y^3的值. x/3=y/4,求(x*x-xy)/(x*x+y*y)的值 已知X+Y=3,XY=-1,求2(X-Y)^4-9(X-Y)^2+12XY |x|/x+y/|y|+xy/|xy|= x^2+xy=12,xy+y^2=15,求(x+y)^2-(x+y)(x-y) x^2+y^2+4y－96=0 求xy x,y为正整数 1-2/x+y=xy,4y+6x=xy.求xy的解? 当x-y=2xy时,求4x-3xy-4y/xy x,y都是自然数,且x(x-y)-y(y-x)=12,求x+y-xy的值 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知x×x×y×y+x×x+y×y+1=4xy,求x,y的值快 4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/（x+2y-12Y²/x-2y)的值 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y) 已知x²+y²-8x+6y+25=0,求（x-y+4xy/x-y）（x+y-4xy/x+y）