{ (x+y)/5+(x-y)/2=3 (x+y)/5-(x-y)/2=1的答案是多少,
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
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
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x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知3x-y=2x-3y+5,则式子x+2y-1的值是多少?
当x=1,y=-2时,代数式x-(x+y)+(x+2y)-(x+3y)+...-(x+99y)的值是多少
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
5x=3y,(2x+y)的平方=5x(x+y)+9
若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值
2元一次方程组的答案(1)2x+3y=40 (2)5x+2y=18 (3)7x+2y=11 y=2x y=-x x-y=