x=3,y=-x+5(x>1) y=-x+5(x≤1),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
x=3,y=-x+5(x>1) y=-x+5(x≤1),y=?
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之1,
设变量xy满足 x+y-3 x-y+1 3x-y+5 z=x+y/x
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
x+y=5; x^y+y^x=17
3X+5y=2 x+y=1