Answer:
It is (a)

Step-by-step explanation:
I hope that is useful for you :)
Answer:
35 different selections of soundtracks are possible
Step-by-step explanation:
Total number of soundtracks available at the store = 7
Enny decides to purchase 3 movie soundtracks.
So, in this problem we have to find in how many ways can Enny chose 3 soundtracks out of 7. The order in which the soundtracks are chosen does not matter e.g soundtracks A,B and C are the same as soundtracks B,C and A.
In an arrangement when the order does not matter, we use combinations to find the total possible number of arrangements or selections.
So, for this problem choosing 3 soundtracks out of 7 means forming combinations from 7 objects taken 3 at a time. This can be represented mathematically as:

The general formula for combinations is:

Using the values, we get:

This means, Enny can make 35 different selections of soundtracks.
Answer:
Y=×^2-9
Step-by-step explanation:
(X+0)^2-9
Use the vertex form, y=a(x-h)^2+k
a=1
h=0
k=-9
And because the parabola opens up the vertex is (0,-9)
The distance from the vertex to a focus of the parabola by using the __ 1/4a__ formula:
1/4(1)
1/4
(h,k+p)
(0,-35/4)
A linear model is a model where the line is the best fit for the data. The correct answer is the graph in the bottom right. It is that box because the line best fits the data.