若x+y:y+z:z+x=3:4:5,则x:y:z=?(急,)

问题描述:

若x+y:y+z:z+x=3:4:5,则x:y:z=?(急,)

令x+y=3t (1)
则y+z=4t (2)
z+x=5t (3)
[(1)+(2)+(3)]/2
x+y+z=6t (4)
(4)-(1) z=3t
(4)-(2) x=2t
(4)-(3) y=t
x:y:z=2t:t:3t=2:1:3
x:y:z=2:1:3