Answer:
The 5th term:
a₅ = 18
Step-by-step explanation:
We know that Arithmetic sequences have a constant rate of change.
Given
- common difference = rate pf change = d = 3
The nth term of the Arithmetic sequence with a₁ and 'd' is defined as
aₙ = a₁ + (n-1)d
Where
a₁ is the first term
d is the common difference
as
a₃ = 12
d = 3
so
Plug in n=3
a₃ = a₁ + (3-1)d
Now Plug in a₃ = 12 and d = 3
12 = a₁ + (3-1)3
12 = a₁ + 2(3)
12 = a₁ + 6
a₁ = 6
so
Formula to find the 5th term
a₅ = a₁ + 4d
Plug in a₁ = 6 and d = 3
a₅ = 6 + 4(3)
a₅ = 18
Therefore, the 5th term:
a₅ = 18
