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:
Step-by-step explanation:
The quadratic formula is:
The discriminant of a quadratic is just the expression under the square root, or 
. This can tell us the number of solutions a quadratic has.
If the discriminant is:
- Positive = 2 real solutions
- Equal to Zero = 1 real double/repeated solution
- Negative = 0 real solutions, but 2 imaginary solutions
Our quadratic equation has a discriminant of 5, which is positive. Therefore, it has 2 real solutions.
20x^2y - 4xy
First, we look at what terms are common between each term.
There is a 4 present in the last term, and 4 is a factor of 20, so that is one factor.
Each term also includes at least one x, and one y, so x and y are also factors.
We can factor a 4, an x, and a y out of this.
<h3><u>4xy(5x - 1) is the fully factored form of this binomial. </u></h3>
