Decide whether the sequence is arithmetic,geometric , or neither.
3,12,21,30,...

Question

Decide whether the sequence is arithmetic,geometric , or neither. 
3,12,21,30,...

anonymous · Answer

If the pattern uses multiplication and division then it is geometric. If the pattern uses addition or subtraction then it is arithmetic

anonymous · Answer

for arithmetic , Tn = a + (n-1)d , a= 1st term = 3 , d= 2nd -1st term = 9
                        T2 = 3 + 9 = 12
                         T3 = 3 + 2 (9) 
                               =3 + 18 = 21
                           T4 = 3 + 3(9) = 3 + 27 = 30
 so Yes the sequence is arithmetic... :)

anonymous · Answer

you see that it keeps gaining 9, so it's adding, therefore arithmetic (:

anonymous · Answer

oh wow thanks babes! both so helpful:)

anonymous · Answer

no problem doll! (:

anonymous · Answer

no problem :)