Answer:
The possible number of CDs she could buy is 1, 2, and 3.
Step-by-step explanation:
First, you have to make an equation to solve to find the answer(s):
- 80 - (18 · x) ≥ 20
- 80 is how much money Felicia has; 18 is for the cost of each CD; x is for the number of CDs; ≥ is no less; and 20 is how much money Felicia needs to have left.
1.) 80 - (18 · 1) ≥ 20
80 - 18 · 1 ≥ 20
80 - 18 ≥ 20
62 ≥ 20
Since 62 ≥ 20 is always true, there are infinitely many solutions.
2.) 80 - (18 · 2) ≥ 20
80 - 18 · 2 ≥ 20
80 - 36 ≥ 20
44 ≥ 20
Since 44 ≥ 20 is always true, there are infinitely many solutions.
3.) 80 - (18 · 3) ≥ 20
80 - 18 · 3 ≥ 20
80 - 54 ≥ 20
26 ≥ 20
Since 26 ≥ 20 is always true, there are infinitely many solutions.
4.) 80 - (18 · 4) ≥ 20
80 - 18 · 4 ≥ 20
80 - 72 ≥ 20
8 ≥ 20
Since 8 ≥ 20 is false, there is no solution.
5.) 80 - (18 · 5) ≥ 20
80 - 18 · 5 ≥ 20
80 - 90 ≥ 20
- 10 ≥ 20
Since - 10 ≥ 20 is false, there is no solution.
Answer: The equation of the parabola is
.
Explanation:
It is given that the focus of the parabola is (-5,-5) and the directrix is y=7.
The standard form of the parabola is,

Where y=k-p is directrix and (h,k+p) is the focus.
Since focus is given,

On comparing,

.... (1)
The directrix is y=7.
.... (2)
Add equation (1) and (2),


Put this value in (1).

Put p= -6, h= -5 and k=1 in the standard form of the parabola.


Therefore, the equation of parabola is
.
Answer:
1 second
Step-by-step explanation:


1/3 of 39,900 equals 1/3*39900
(1/3)*(39900/1)= 39900/3
39900/3= 13300
Final answer: 13,300