令x/2=y/3=z/5=k
x=2k
y=3k
z=5k
2x+y+3z=88
2*2k+3k+3*5k=88
4k+3k+15k=88
22k=88
k=4
x=2k=2*4=8
y=3k=3*4=12
z=5k=5*4=20