Question 982687
let the numbers be 

a-d, a , a+d

a(a^2-d^2) =224

a+d = 7(a-d)

a+d = 7a-7d
6a=8d
a=8d/6 = 4d/3



a(a^2-d^2) =224
4d/3((4d/3)^2 -d^2)=224
d(16d^2/9 -d^2) =56*3

d(16d^2-9d^2)/9)=56*3

d(7d^2) = 56*3*9

7d^3= 56*3*9/7

d^3= 8*3*9

d=6
a=8

the numbers 2,8,14