已知4x—3y=-5,3x+4y=3,则21x+3y
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知4x—3y=-5,3x+4y=3,则21x+3y
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知x-2y/2x+3y=3/4,则x:y=
已知4x=5y,那么(3x+y)/(x-2y)=
已知3X=4X,5Y=6Z求X+Y:Y+Z
已知x,y>0 2x+y+3=xy 求5x+4y最小值
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值