{4x+3y=1,2x+y=2 ｛2x+3y=2,3x-2y=3

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 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 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 9y=3x-(x-1),4(x+y)-(2x+4)=8y 4x(x-y)-(2x-3y)(2x-3y) x=1 y=-1 [(y-2x)(-2x-y)+4(x-2y)平方]/3y,其中x=1,y=-3 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 二元一次方程 ：2(x+y)-(x-y)=3 (x+y)-2(x-y)=1