设an的公差是d
∴a3=a1+2d,a9=a1+8d
a2=a1+d,a4=a1+3d,a10=a1+9d
∴a1+a3+a9=3a1+10d,a2+a4+a10=3a1+13d
∵a1,a3,a9依次成等比数列
∴a3/a1=a9/a3
∴a1^2+4d^2+4a1d=a1^2+8a1d
∴a1=d
∴(a1+a3+a9)/(a2+a4+a10)=(3a1+10d)/(3a1+13d)=13d/16d=13/16