0.4x+0.3y-0.2z=40.6x-0.5y+0.3z=50.3x+0.2y+0.5z=22

0.4x+0.3y-0.2z=40.6x-0.5y+0.3z=50.3x+0.2y+0.5z=22 三（四）元一次方程组!1.2z-6=-2(x+3y)3(5y+x)=6-7z4(x+z)=9+9y2.2x-5y=-117y+4z=55x+2z=23.0.4x+0.3y-0.2z=40.6x-0.5y+0.3z=50.3x+0.2y+0.5z=224.x/2+3y/4+5z/3=455.1x+6y/5-4z=150.1x-0.4y+4z/5=55.x+y=7y-z=1z+2u=4u-3x=-11 x:y=三分之一:二分之一,x:z=0.3:0.2 x：y：z是多少? (x+y-z)(x-y+z)= 解三元一次方程组!请写具体的过程!（1）2x+3y=10 (2)x:y=3:2 (3)4x-9z=17 (4)0.4x+0.3y-0.2z=45z+2z=6 y:z=5:4 3x+y+15z=18 0.6x-0.5y+0.3z=53y+5z=4 x+y+z=66 x+2y+3z=2 0.3x+0.2y+0.5z=22第一个错了！（1）2x+3y=10 5z+2x=63y+5z=4 x,y,z不是0.3z=4y,z=3x求（x+y）：（x+z）. X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? z+=x>y?++x: 这道三元一次方程怎么解啊X+Y+Z=10000.95X+0.8Y+0.35Z=9000.05X+0.2Y+0.65Z=1000.05X+0.3(Y+Z)=100 0.95X+0.7(Y+Z)=900 (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 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? fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 x=y; y=z; z=x/y (x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之（x-z)(y-z)=?第三部分那个是 （y+z-2x)(x-2y+z)分之（x-z)(y-z) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x)