Question

用消元法解方程：5x-3y+6z=6,x+1=(3z-4y)/2,10x+12y-6x=-3

Answer 1

5x-3y+6z=6 (1)

x+1=(3z-4y)/2

2x+4y-3z=-2 (2)

10x+12y-6x=-3,错了

是10x+12y-6z=-3 (3)

(1)+(3)

15x+9y=3

5x+3y=1 (4)

(1)+2*(2)

5x-3y+4x+8y=6-4

9x+5y=2 (5)

(4)*5-(5)*3

25x-27x=5-6

x=1/2

y=(1-5x)/3=-1/2

z=(6-5x+3y)/6=1/3