Question

if an=3-21n, then find the common difference d.​

Answer 1

Answer:

d=-21

Step-by-step explanation:

an=3-21n

a1=3-21×1

a1=3-21

a1=-18

a2=3-21×2

a2=3-42

a2=-39

d=a2-a1

 =-39-(-18)

 =-39+18

 =-21

the difference =-21