Respuesta :

Step-by-step explanation:

13) the difference does not equal So

     It is not arithmetic

14)It is arithmetic

    d= 30-40=20-30=10-20=-10

explicit formula:

a(n) = a +(n-1)d

a(n) = 40 +(n-1)-10

a(52) = 40 +(52-1)-10

         =40-5100

         =-5060

hope this helps