X是单数.(77-X)÷X=Y.5,求X和Y
|x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少
已知x+y=-5,x*x+y*y=19求xy和(x-y)*(x-y)的值
已知x+y=-5,x*x*x+y*y=19,求xy和(x-y)的值
求因式分解(x-y)²-2(x-y)³和(x+y)(x-y)-x(x-y)
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+.
3x+2y=5 3y+2x=5 求x和y
求x和y,
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
已知:4x = 5y,求(x+y) :y
已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值
已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值.