解方程 (x+y)/3=(2x+z)/4=(2z+2y)/5
x+y+z=36
(x+y)/3=(2x+z)/4=(2z+2y)/5 =k
x+y=3k 2x+z=4k 2z+2y=5k
x+y +2x+z+ 2z+2y=12k=3(x+y+z)=108
k=9 x+y=27 2x+z=36 2z+2y=45
x+y+z=36 z=9 x=27/2 y=27/2