Answer:
Arithmetic sequence
for 
Step-by-step explanation:
We are given that a sequence

We have to identify the sequence as arithmetic or geometric and write an explicit formula .







When the difference of consecutive terms is constant then the sequence is an arithmetic.
Hence, the sequence is an arithmetic.

for 
Answer:
x^2-1
Step-by-step explanation:
Answer:
48 ways
Step-by-step explanation:
There are 52 cards in a deck and four nines. This means that nines account for 4/52 of the deck. The opposite of 4/52 (idr the math word for that) is 48/52. Therefore, there are 48 other ways that a card other than nine can be obtained.
<span>Residual value is the difference between the observed value of the dependent variable (y) and the predicted value (ŷ) in a data set.
i.e. Residual value = given value - predicted value
From the table, the residual value corresponding to a has 4.1 as the given value and 4.5 as the predicted value.
Therefore, a = 4.1 - 4.5 = -0.4
Similarly, </span><span>the residual value corresponding to b has 7.2 as the given value and 7.05 as the predicted value.
Therefore, b = 7.2 - 7.05 = 0.15
</span>
Therefore, a = -0.4 and b = 0.15