x+y=8,xy=15,求x^3y+2x^2y^2+xy^3

x+y=8,xy=15,求x^3y+2x^2y^2+xy^3 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) 已知xy/x+y=2,求代数式8x-5xy+8y/-x+3xy-y的值 3X^2+XY+Y=15 求XY. 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y x^2+xy=12,xy+y^2=15,求(x+y)^2-(x+y)(x-y) 已知1/x+1/y=8,求2x-3xy+2y/x+2xy+y的值 已知x,y为正整数,并且xy+x+y=71,x^2y+xy^2=880,求3x²+8xy+3y² x*x-xy=-3,2xy-y*y=-8,求2x*x-4xy+y*y的值 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知x-xy=8,xy-y=-9,求x+y-2xy的值 当x-y=2xy时,求4x-3xy-4y/xy 已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=? 求（3x^+y^-5xy）-【2x^-（-4xy-y^+7x^）】=? 已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理. 已知(x+y):y=8:3,求2x+5y/3x-y和x^2-xy/y^2+3xy的值 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y)