DECA=10, decagon = 10 sides.
since each side is 1.8 long, all 10 sides will be 10*1.8 or 18 units long, so that'd be the perimeter then,
Answer:
1. 
- Degree: 2
- Number of terms: 3
2. 
- Degree: 3
- Number of terms: 2
3. 
- Degree: 4
- Number of terms: 2
Step-by-step explanation:
For this exercise you need to remember the multiplication of signs:

1. Given:

Apply the Distributive property:

Add the like terms:

You can idenfity that:
- Degree: 2
- Number of terms: 3
2. Given:

Add the like terms:

You can idenfity that:
- Degree: 3
- Number of terms: 2
3. Given:

Apply Distributive property:

Add the like terms:

You can idenfity that:
- Degree: 4
- Number of terms: 2
4=2.25x add 2x on both sides
1.78=x subtract 2.25 on both sides
B..............
c>=3 and n<0 and p<=(9-3 c)/n
This is my work hope this helps.