如题 若2x+y=0,则x^2=xy+y^2/2xy-x^2的值为 为什么我算来算去都是7/3?知道的写详细过程

若实数x,y满足x^2-xy-y^2 =0,则x/y=? 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+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= 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y-2x=0,则分式(x^2+xy+y^2)/(x^2-xy+2y^2)= 若x²+xy-2y²=0,则x²+3xy+y²/x²+y² 若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值 若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少? 若xy/x+y=2,则3x-5xy+3y/-x+3xy-y=?/是分之 若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少? 若xy/x+y=2,则3x-xy+3y/-x+3xy-y= x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 若x-y=4,xy=1,则(2x+y-2xy)-(3x+2y+xy)-(4xy+3y-5x)= 若2x+y=0,求(x^2+xy+y^2)/(2xy-x^2) 若集合{x,xy,lg(xy)}={0,|x|,y},求log8(x^2+y^2) {x,xy,lg(xy)}={0,|x|,y} 则log8（X^2+Y^2） 已知x y=6,xy=-3,则3x-2xy 3y的值等于?如题补充：是已知x+ y=6,xy=-3,则3x-2xy +3y的值等于?