(3x+2y=268 2x+3y=212) x-y=56 x=56+y 3(56+y)+2y=268 168+5y=26

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (3x+2y=268 2x+3y=212) x-y=56 x=56+y 3(56+y)+2y=268 168+5y=26 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 5(x+y-2)=3-y 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20