Negative because if you take away from a negative, your just making it smaller... hope this helps!
Answer:

Step-by-step explanation:
Given


Required
The explicit formula
First, calculate 
Set n=2; So:


Substitute -25 for 


Calculate the common difference (d)



So, the nth term is:


Open bracket

Collect like terms


Answer:
the ratio would be 6.75:4.5:3:2
Step-by-step explanation:
replace d and c with
d=2 and c=3
Then using proportion multiplication, you will find that b is 4.5
now replace all b with 4.5.
Then again using proportion multiplication, you will get a is 6.75.
Plug in a, b, c, d in the ratio and you get 6.75:4.5:3:2
Answer:
3
Step-by-step explanation: