(3x+2y)/3=(5y+12x)/3=－1

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 12y(x-y)^2-8(x-y)^3=? (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 3x+y=2 -y/x+y=123x+y=2 （-y/x）+y=12 {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 化简:5(x-y)+2(x+y)-3(x-y) 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 2(x-2y)²-7(x-2y)³+3(2y-x)²+(2y-x)³合并同类项 这个式子2（x-2y)²-7（x-2y)³+3(2y-x)²-(2y-x)³=2（x-2y)²-7（x-2y)³+3(x-2y)²+(x-2y)³=5(x-2y)²-6(x-2y)³=(x-2y)²(5-6x+12y) (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一