{2X=5(X+Y) 3X-10(X+Y)=2
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(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
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
5(x+y)-2x=0 3x-10(x+y)=2
已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y
{ x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3