X:Y:Z=1:2:3 2X+Y-3Z=15
3个回答
X:Y:Z=1:2:3
y=2x,z=3x,代入 2X+Y-3Z=15 得
2x+2x-3*3x=15
x=-3
y=-6
z=-9
相关问题
(1)3x+4y=15 2y-z=2 x+2z=9 (2) x+y+z=8 2x+3y-z=6 3x-y+z=8 (3)
① 15又2/3*(-14又1/3) ② [2x^2-(x+y)(x-y)][(z-x)(x+z)+(y-z)(y+z)
x+2y+3z=15 (x+2z)/3=(2y-3z)/4=5
{15x-3y+2z=1 3x+4y-z=-18 z=13
4X-5Y+2Z=1,8X-3Y-Z=15,5X+2Y-3Z=18
证明:(y+z-2x)3+(z+x-2y)3+(x+y-2z)3=3(y+z-2x)(z+x-2y)(x+y-2z).
三元一次方程1.{3x-y+z=4,{2x+3y-z=12,{x+y+z=6 .2.{4x-9z=17,{3x+y+15
2x-y=7 x+y+z=25x+3y+z=2 x-2y+z=-1 3x-4z=4 x+2y+3z=-1x+y-z=6x
若x+y+z=2,x^2+y^2+z^2=2,1/x+1/y+1/z=1/3则 x^3+y^3+z^3=
x+2y+3z=1 2x+3y+z=2 3x+y+2z=3