求方程x+2y-3x=4,3x-2y+x=6,3x+2y-5x=8的解x+2y-3x=4,3x-2y+x=6,3x+2y-5x=8

求方程 dy/dx+x(y-x) +x^3(y-x)^2=1的通解~ 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知x=3分之一,y=-2分之一,求代数式x-(x+y)+(x+2Y)-(x+3y)+(x+4y)...-(x+2009y) 求适合方程(x^2-4x-5)+(y^2+3y-4)i=0的实数x,y 已知方程4x+2y=12和2x+3y=16求x和y 解方程x-3y+1=2x-y=3x-2y+4 解方程x-3y+1=2x-y=3x-2y+4 实数x,y满足方程4x+3y-1=0,求x^2+y^2的最小值 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 已知方程3(X-Y)^2-5X-2=2X-7Y-4.求X-Y的值 已知方程3(X-Y)^2-5X-2=2X-7Y-4.求X-Y的值 解方程3(2X-Y)+4(X-2Y)=87 2（3X-Y)-3(X-Y)+82 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 3分之x+y+2分之x-y=2,4(x+y)-7(x-y=-2用换元法解方程 2(X-Y)/3=(X+Y)/4 -1 6(X+Y)=4(2X-Y)+16解方程