Question

x+y=1/2,y+z=1/3,z+x=-1/4解方程（3元一次方程）

Answer 1

x+y=1/2 (1)

y+z=1/3 (2)

z+x=-1/4 (3)

(1)+(2)+(3)

2(x+y+z)=7/12

x+y+z=7/24 (4)

(4)-(2) x=7/24 -1/3=-1/24

(4)-(3) y=7/24 -(-1/4)=13/24

(4)-(1) z=7/24 -1/2= -5/24

x=-1/24 y=13/24 z=-5/24