Question

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

Answer 1

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

Answer 2

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... :)

Answer 3

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

Answer 4

oh wow thanks babes! both so helpful:)

Answer 5

no problem doll! (:

Answer 6

no problem :)