A={(x,y) | y-3/x-2=2},B={(x,y) | y=(a-2)x-3}.若A∩B=φ,求a的值.

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 已知方程组 2x+y=3a x-2y=a 求x/y (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x+y)(2x-3y)=? A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 (x-2y)^5=a0(x+2y)^5+a1(x+2y)^4*y+a2(x+2y)^3*y^2+a3(x+2y)^2*y^3+a4(x+2y)y^4+a 解关于x、y的方程组2x-y=a,2x+y=-3 已知3x+2y=a,2x+3y=b,则(x+y)(x-y)=? x+y=a,x-y=b.求2x-3y等于 集合A={（x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 方程组:3（x+y)-a(x-y)=16,2(x+y)+b(x-y)=15的解是什么? 如果方程组x-y=a-3,2x+y=5的解x、y满足x>0,y 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值