Answer:
Tn = 12(-1/2)^n
Step-by-step explanation:
We have the nth term of a geometric sequence as
Tn = ar^n-1
a is the first term
r is the common ratio
n is term number
by dividing the second term by the first, we can have the common ratio
We have this as -6/12 or 3/-6 = -1/2
a the first term is 12
So we have the explicit formula as;
Tn = 12(-1/2)^n
