4x-3y= -5,4y+3x=3；x、y等于几

（5x+3y)(3y-5x)-(4x-y)(4y+x)= 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 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 （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 3X=5Y （X+Y)*3X=(2Y+X)*4+2*2 （3x-y)(y+3x)-(4x-3y)（4x+3y)=? (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian {3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 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 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9