Focus has coordinates (0, a)
a = -3
Thus, 4a = 4(-3) = -12
Because a is negative, we know it will be a concave down or concave left parabola. Hence, A and D can be eliminated. And we know it has to be B because the directrix is the horizontal line y = 3. Hence, the equation of the parabola becomes:

or
If you are just dividing percent's, then each grade would have 12.5 percent.
t=D/r
Divide r by both sides to get t by itself.
Answer:
13. 
12. 
11. 
10. 
9. 
8. 
7. 
6. 
5. 
4. 
3. 
2. 
1. 
DON'T GET HOOKED
Step-by-step explanation:
13. 
12. ![5[r + 4] = 45 \\ \\ r + 4 = 9 \\ \\ 5 = r](https://tex.z-dn.net/?f=5%5Br%20%2B%204%5D%20%3D%2045%20%5C%5C%20%5C%5C%20r%20%2B%204%20%3D%209%20%5C%5C%20%5C%5C%205%20%3D%20r)
11. 
10. 
9. 
8. 
7. 
6. ![3[a + 5] = 24 \\ \\ a + 5 = 8 \\ \\ 3 = a](https://tex.z-dn.net/?f=3%5Ba%20%2B%205%5D%20%3D%2024%20%5C%5C%20%5C%5C%20a%20%2B%205%20%3D%208%20%5C%5C%20%5C%5C%203%20%3D%20a)
5. 
4. 
3. 
2. 
1. 
D O N ' T G E T H O O K E D
___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___
6 1 10 3 9 8 7 13 2 12 11 5 4
I am delighted to assist you anytime!
2x-6=90 would be the answer