2x-8=-x 4x+3y=72x-8=-x 4x+3y=7写错了，是2y-8=-x

9y=3x-(x-1),4(x+y)-(2x+4)=8y x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y {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) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian [(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x= x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? [(2x-y)^2-y(y-4x)-8x]其中x=-1/2 化简y=|x-1|+|x-4|-|3x-8| 3(x+y)-2(x-y)=4; 3(x+y)+2x-2y=8 3(x+y)-2(x-y)=4; 3(x+y)+2x-2y=8 解方程组 3^x+2x=y,x 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 计算：（x-3y)(x+7y)化简：(-4x+1)(2x+3)-(-8x)(x+1)先化简,再求值：2（x-8)(x+5)-(2x-1)(x+2),其中x=-7 [(2x+y)²-y(y+4x)-8x】/4x,其中x=-1,y=2005 急 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