5X-3y=-1,2X+3y=8的解

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 用适当的方程解方程组2(x+y)-(x-y)=8 (x+y)-2(x-y)=15 2x+1=5(y+2) (3x+2)-2(y+7x)=16 (x+2y)(x-2y)-(2x-y)的平方+(3x-y)(2x-5y)其中x=-1 y=13分之1 x-y/x+y=-1/2,x*x-xy-2y*y/x*x-3xy+2y*y的解是多少?同上,请将过程写出, 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 请你仔细观察方程组的特点,解出方程组的解.(1) 3x=2y+26x-5y=2(2) 2(x+y)-3(x-y)=33(x+y)-(x-y)=8 证明：代数式[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]/xy 的值为x,y的值无关 解方程 (x+1)^5/(-1-x)^4=3x+7一定要100%正确阿. {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.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 2x+2y-x+y=3;x+y-2x+2y=1 方程组的解 如果方程组x-y=a-3,2x+y=5的解x、y满足x>0,y { (x+y)/5+(x-y)/2=3 (x+y)/5-(x-y)/2=1的答案是多少, 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 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) {x+y}/2+{x-y}/3=5 {x+y}/2-{x+y}/3=-1 解二元一次方程 3Q!| {x+y}/2+{x-y}/3=5 | {x+y}/2-{x+y}/3=-1