10*X+2*Y+0.5*z=100老牛=10元 大牛=2元 小牛=0.5元 要100元买100头牛

10*X+2*Y+0.5*z=100老牛=10元 大牛=2元 小牛=0.5元 要100元买100头牛 解方程 Y=X+Z Y-Z=2 100Z+10Y+X-(100X+10Y+Z)=99 Y=X+ZY-Z=2100Z+10Y+X-(100X+10Y+Z)=99 请高手帮我解几道3元1次的方程组!好的100分,x+2y+3z=15x-y+7z=20x+3y+2z=14x+y-z=3y+z-x=5z+x-y=7x+y-z=0.5x-3y+2z=03x+2y-z=23x-2y=12y+3z=2x+5z=315x-3y+2z=13x+4y-z=-18z=136x-y-z=32x-4y+8z=53x-6y-z=10x+y=3y+z=5x+z=6 紧急..x+y+z=20x+2y+1.5z=367x+10y+6z=100 解一道三元一次方程x+y+z=13,y-2=z,100z+10y+x+99=100x+10z+y. 10X+Y+1/3Z=10Y+X 10X+Y+2/3Z=100X+Y x+y+z=12 x-y+z=2 x-z+y+a=90 x+y+a+z=100,求x y z a X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 解方程组：X+Y+Z=100,10X+5Y+0.5Z=100 X=3z X+y+z=12 X+2y-2z=10 2x+z=10 x+y-z=4 3x-y-z=0 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? x+2y+3z=23 y-z=5 x+2z=10 100x+10y+z=27(x+y+z) x+z=y+1 100z+10y+x-100x-10y-z=99 解方程组100x+10y+z=27(x+y+z) x+z=y+1 100z+10y+x-100x-10y-z=99 .急. f(x,y,z)=(x^2+y^2)^0.5+z^1.5,求 ∂f(x,y,z)/∂y (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证? 3X+2y+z=20 x+y+z=10 Y=3X