{3X-4y=18 ,{6Y-Z=-19,{2X-3Y+4Z=17

问题描述:

{3X-4y=18 ,{6Y-Z=-19,{2X-3Y+4Z=17

3x-4y=18 ①
6y-z=-19 ②
2x-3y+4z=17 ③
由①得:x=6+4y/3 ④
由②得:z=6y+19 ⑤
将④⑤带入③:12+8y/3-3y+24y+76=17
x=2
y=-3
z=1