What is the explicit formula for the sequence?

−1, 0, 1, 2, 3, . . .

an = n + 2

an = n − 2

an = an−1 − 2, where a1 = 3

an = an−1 − 2, where a1 = −1

= n - 2

Step-by-step explanation:

Note the difference between consecutive terms is constant, that is

0 - (- 1) = 0 + 1 = 1

1 - 0 = 1

2 - 1 = 1

3 - 2 = 1

This indicates the sequence is arithmetic with n th term

= a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 1 and d = 1, thus

= - 1 + n - 1 = n - 2

$25

step-by-step explanation:

25 - 4.50 = 20.5

20.5 / 2 = 10.25

10.25 + 10 = 20.25

20.25 - 12.50 = 7.75

therefore the answer is $25 as shown as the first number.

b, i believe, but not sure.