y+19=x x=1.5y 求x?
x+x+x=15,x+y+y=19,求y-x等于几
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
已知x+y=-5,x*x+y*y=19求xy和(x-y)*(x-y)的值
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
x+x+x+y=52 y+y+y+x=36求x
已知x+y=-5,x*x*x+y*y=19,求xy和(x-y)的值
求y'=y/(y-x)
(x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少
若x+7y=y-3x,求x
y=ln(x^2+e^x) 求Y'X
|x-y |=x-y |x |=1999 |y |2000,求x+y的值