The rules for multiplying powers with the same base is you are basically doing the pemdas method Please Excuse My Dear Aunt Sally pemdas
C = $7s
independent variable ie the changing variable is s
dependent variable ie the non changing variable is c
Answer:

With the vertex 
We see that b = -10 and a = 2 and then the vertes wuld be:

And the best option is:
b. (-10,2)
Step-by-step explanation:
For this problem we have the following function:

And if we compare this expression with the general expression for a parabola given by:

With the vertex 
We see that b = -10 and a = 2 and then the vertes wuld be:

And the best option is:
b. (-10,2)
Answer: There are a lot of possibilities
- she was taking a break
- she forgot
- she was too busy
- she was injured
- she didn't want to
- there was an emergency
I guess you could pick your favorite...