Answer:
Geometric Sequence
Step-by-step explanation:
1. Check the difference.
The difference between the 1st and 2nd term

The difference between the 2nd and 3rd term

The difference is not the same. Therefore, it is not an arithmetic sequence.
2. Check the ratio
The ratio between the 1st and 2nd term

The ratio between the 2nd and 3rd term

The ratio is the same. Therefore, it is a geometric sequence.
Always
a=b
subtract c from each side
a-c = b-c
the value of c that makes the expression a perfect square binomial is c=4 .
<u>Step-by-step explanation:</u>
Here we have , an expression x2 + 4x + c or ,
. We need to find the value of c that makes the expression a perfect square binomial. Let's find out:
We have , 
⇒ 
⇒ 
Now , we know that 
Comparing above equation , to
we get ;
⇒
{
}
⇒ 
⇒ 
Therefore , the value of c that makes the expression a perfect square binomial is c=4 .