3x+4y=2 2x－y=5 求X与Y的解刚学不太会,

3x+4y=2 2x－y=5 求X与Y的解刚学不太会, 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 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 方程组:3y=x+4 ,2x+5y=-19 求x与y的值 若／X+Y-9／+（2X-Y+3)=0求X与Y的值 求5x-2y=x-y=4x-3y-2的解 已知(x+2y)(2x-3y)=y(y-4x),试求x/y的值 (3x+2y)+(5x-y)i=17-2i.求x与y 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 y=3(x-y),x=2(x-y)求x,y的值 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 2x-5+y/3=x+3y/4+7与10(x-y)-4(1-x)/3-y=0 求方程组的解 已知4份之3x+2y=6份x-y+1=5份之2x+y,求x与y的值