Question

1.) In the following problem, write the first five of the terms of the arithmetic sequence.

a1=16.5
d=0.25


2.) Find a the correct formula for the an for the arithmetic sequence.

a1=-1
d=5

Answer 1

(1)
In arithmetic sequence, we just add the common difference, d = 0.25, to a term to get the next term. Therefore,
a1 = 16.5
a2 = 16.5 + 0.25 = 16.75
a3 = 16.75 + 0.25 = 17.0
...and so on.

(2)
General formula for arithmetic sequence:
an = ao + (n-1)d
where
an = nth term
ao = first term
n = number of terms
d = common difference

Since you have a1 = -1 and d = 5, thus,
an = -1 + 5(n-1)

hope this helps~ `u`

Answer 2

1.)

a1 = 16.5

a2 = 16.5 + 0.25 = 16.75

a3 = 16.75 + 0.25 = 17

a4 = 17 +0.25 = 17.25

a5 = 17.25 +0.25 = 17.5


2.)

an = a1 + ( n - 1 ) * d

an = - 1 + ( n - 1 ) * 5

OR

an = 5 ( n - 1 ) - 1