1.xy-3x=40;x=52.7x-xy=-18;x=-63.3xy-28=16x;x=44.9y+6xy=30;x=-65.y-2xy=15;x=-16.4x+7y+5xy=0;x=1

1.xy-3x=40;x=52.7x-xy=-18;x=-63.3xy-28=16x;x=44.9y+6xy=30;x=-65.y-2xy=15;x=-16.4x+7y+5xy=0;x=1 |x|/x+y/|y|+xy/|xy|= （-3x^y+2xy)-( )=4x^+xy 因式分解x^3+2xy-x-xy^2= x/3=y/4,求(x*x-xy)/(x*x+y*y)的值 (x^3-2x^2+xy^2)/(x-y)+(x+y)(y-x)=? 先化简,再求值：x^x+xy/x^x-xy^(y^y-xy/xy)除以(x+y),其中x=1/3,y=-3 化简:xy分之3x^2+2xy-xy分之2x^2-xy= (1)已知x+y=6,xy=-3,x^2y+xy^2=(2)x*[2-(1/x)]+(x/x^2-2x)*(x^2-4) x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? 实数x,y满足x乘以1-x=y-2 + x-1.求3x²+xy-y²除以x²-xy+y²的值.x*根号1-x=根号y-2+根号x-1 先化简,再求值：-4x+7x-5-3x-6x+2,其中x=-2分之1 4xy-3x-xy先化简,再求值：-4x+7x-5-3x-6x+2,其中x=-2分之14xy-3x-xy+y+x-3xy-2y+2x+x,其中x=-5,y=-1 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? (x^3+3x^2-2xy^2+1)+(-xy^2+x^2-2X^3+2)+(x^3-4x^2*y+3xy^2-8)= 已知xy+x=-3,xy-y=2求代数式-x-[2y-2(xy+x)^2+3x]+2[x+(xy-y)^2]的值 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 3xy-( )=5xy-2 x-(5x-3y)+( )=-2x+2y -3(2x-xy)-4(-6+xy+x.其中x=1,y=-1