2x+3y=-1 4x-3y=8

9y=3x-(x-1),4(x+y)-(2x+4)=8y {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=? (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 先化简 再求值 (2x-y)(y+x)-(x-2y)(2y+x)-(-3y+x)^2其(√x+1)+y^2+4=-4y 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 1/4(x+y)+3/8(x-y)=1,3/4(x-y)-1/2(x+y)=1, 3分之2(x-y)-4分之x+y=-1 8(x+y)-4(2x-y)=16 解方程组8/(x+y) +(x-y)/2=3,6/(x+y)-(x-y)/4=1 解下列方程组：{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= [(y-2x)(-2x-y)+4(x-2y)平方]/3y,其中x=1,y=-3 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian [(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3 先化简,再求值：[(x+y)(x-y)-(x-y)^2+2y(x-3y)]/(-4y),其中x=1,y=-2