Answer: 12$
Step-by-step explanation:
We need to round 79.45 to the nearest 10 dollars, which is 80.
We can then get 15% of it easily since its a whole number by adding 10% (8) and 5% (4) to get an estimate of around 12 dollars.
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)
3 hours. I think. X represents the # of hours and they equal the same after exactly 3 hours.
its is the closet one too the right one