若x^4+y^4=15,xy^2-x^2y=-5,求x^4-y^4+3xy^2-x^2y-2xy^2+2y^4

若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= （-3x^y+2xy)-( )=4x^+xy 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 若x-y=3,xy=15,整式（3x-4y+5xy)-(2x-3y-5xy)的值是 若x-y/x+y=2,则x2+2xy+y2/4xy=多少 当x-y=2xy时,求4x-3xy-4y/xy 若x+y=4 x-y=6 求xy(x^2+y)-y^2(xy+2x)-3xy的值求值 1-2/x+y=xy,4y+6x=xy.求xy的解? 若1/x+1/y=3,4y-2xy-4x/3x+xy-3x等于多少 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? x-2y=15,xy=-25,求x*x+4y*y-1 若(2x-14xy-2y)除以(x-2xy-y)=4,则1/x-1/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. 若|x-3|+（y+2）=0,则（x-y+4xy/x-y）（x+y-4xy/x+y）的值是 若|x-3|+（y+2）²=0,则（x-y+4xy/x-y）（x+y-4xy/x+y）的值是 若X分之一减y分之一=3,求（5x+2xy-5y）/（x-4xy-y) 若x分之一-y分之一=3,求x-4xy-y分之5x+2xy-5y