2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
问题描述:
2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
答
2X+4Y+3Z=9 (1)
3X-6Y+5Z=11 (2)
5X-6Y+7Z=13 (3)
(1)×3+(2)×2
12X+19Z=49 (4)
(3)-(2)
X+Z=1 (5)
(5)×19-(4)
7X=-30
X=-30/7
Z=1-X=37/7
Y=(9-2X-3Z)/4=3/7