∵{an}是等差数列
∴a2=a1+d
a4=a1+3d
∵a1,a2,a4依次成等比数列
∴(a2)^2=a1*a4
即（a1+d)^2=a1(a1+3d)
a1^2+2a1+d^2=a1^2+3a1d
a1d=d^2
∵公差d≠0,
∴a1=d
∴a4=4a1 a7=7a1 a10=10a1 a2=2a1
式子要是有括号是（a1+4a1+10a1）/（2a1+4a1+7a1）=15a1/13a1=15/13
式子要是没有括号是a1+4a1+10a1/2a1+4a1+7a1=5a1+5+11a1=16a1+5