Question

方程组9X-5Y+Z=-6 9X+Y+4Z=3 -9X+3Y-5Z=0 3元一次方程

Answer 1

9X-5Y+Z=-6 (1)

9X+Y+4Z=3 (2)

-9X+3Y-5Z=0 (3)

(2)-(1)

6Y+3Z=9

2Y+Z=3 (4)

(2)+(3)

4Y-Z=3 (5)

(4)+(5)

6Y=6

所以

Y=1

Z=3-2Y=1

X=(3-Y-4Z)/9=-2/9