{(x+y)/2=(3x+4y)/5,(x+y)/2=1,

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 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 3X=5Y （X+Y)*3X=(2Y+X)*4+2*2 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= (x-2y)^5=a0(x+2y)^5+a1(x+2y)^4*y+a2(x+2y)^3*y^2+a3(x+2y)^2*y^3+a4(x+2y)y^4+a {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 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] （5x+3y)(3y-5x)-(4x-y)(4y+x)= 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解