Question

求4x-9z=17 3x+y+15z = 18 x+2y+3z=18 的值

Answer 1

4x-9z=17 (1)

3x+y+15z = 18 (2)

x+2y+3z=18 (3)

由(2)*2-(3)得

6x+2y+30z-x-2y-3z=36-18

5x+27z=18 (4)

由(1)*3+(3)得

12x-27z+5x+27z=51+18

17x=69

x=69/17

y=262/51

z=-13/153

题目有误,求得x、y、z值不能满足3个方程