X-Y=Z X+Y+Z=80已知Y等于10求X和Z
X-Y=Z X+Y+Z=80已知Y等于10求X和Z
已知X+Y=12 Y+Z=10 求X Y Z各等于几
已知x+y-z/z=x-y+z/y=-x+y+z/x,且xyz不等于0,求分式[(x+y)(x+z)(y+z)]/xyz
已知:(x+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z)
已知3x+7y+z=315和4x+10y+z=420,求x+y+z
已知x/z=ln(z/y),求z对x和y的偏导.
已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/
已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/(
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
(x+y-z)(x-y+z)=
已知x-y+z=0,求(x²-y²-z²)-4y²z²等于多少?
x+y=10 y+z=15 z+x=20 求x,y,z等于多少?