設(shè)后三個是a-d,a,a+d
則第一個是(a-d)^2/a
所以a-d+a+a+d=19,a=19/3
(a-d)^2/a+a-d+a=13
所以(19/3-d)^2/(19/3)+19/3-d+19/3=13
d=(19±√209)/2
(a-d)/a=(59+3√209)/6或(59-3√209)/6
a-d=(-19-3√209)/6或(-19+3√209209)/6
a+d=(95+3√209)/6或(95-3√209)/6
所以是
(59-3√209)/6,(-19+3√209)/6,19/3,(95-3√209)/6
或(59+3√209)/6,(-19-3√209)/6,19/3,(95+3√209)/6