Question

x+y=3m和y+z=4m和z+x=5m 求此方程解

Answer 1

x+y=3m (1)

y+z=4m(2)

z+x=5m (3)

(1)+(2)+(3)

2(x+y+z)=12m

x+y+z=6m (4)

(4)-(2),x=2m

(4)-(3),y=m

(4)-(1),z=3m