Answer:
Both sequences are arithmetic. The first sequence has a common difference of 2, and the second sequence has a common difference of 4.
Explanation:
Let's remember the definitions of arithmetic and geometric sequences:
the difference between one term and the next is a constant (always the same), i.e. we add the same value to one term to get the next one.
each term is found by multiplying the previous term by a constant.
So, in one case we add the same constant and in the other we multiply it.
Let's analyze our sequences:
6, 8, 10, 12, ...
The difference between the first term and the second one is 8 - 6 = 2
The difference between the second term and the third one is 10 - 8 = 2
And the last difference is 12 - 10 = 2
We are adding 2 in each term, so it's an arithmetic sequence.
Let's see it's not a geometric sequence:
We need to multiply 6 by 4/3 to get 8, but if we multiply 8 by 4/3, we get 32/3 and that's not the third term. So, we are not multiplying by a constant in this case.
16, 20, 24, 28, ...
If we do as before, we get that we add 4 in each term to get the next one, so it's an arithmetic sequence.
It's not a geometric sequence because we need to multiply 16 by 5/4 to get 20, but 20 * 5/4 = 25
24