Question

How do I solve this arithmetic sequence?

Answer 1

Arithmetic sequence means you add a constant d to a term to get the next.
In other words, a1 = 13, then
a2 = a1 + 4 = 13 + 4 = 17
a3 = a2 + 4 = 17 + 4 = 21
And so on.
There is a formula to find larger terms.
Since a2 = a1 + 4
a3 = a2 + 4
= (a1 + 4) + 4
= a1 + 2*4
a4 = a3 + 4
= a1 + 2*4 + 4
= a1 + 3*4
And so on, notice the pattern:
an = a1 + (n-1)*d
a6 = a1 + 5*d = 13 + 5*4 = 13 + 20 = 33

Answer 2

The 6ᵗʰ term of this sequence is 82

Explanation:

Here,

First Term = a₁ = 13

Common Difference = (d) = 4

Now, For 6ᵗʰ term, n = 16

aₙ = a + (n - 1)d

a₆ = 13 + (6 - 1) × 4

a₆ = 13 + 5 × 4

a₆ = 13 + 20

a₆ = 33

Thus, The 6ᵗʰ term of this sequence is 33

-TheUnknownScientist