Explanation:
The formula for getting the ROI or Return of Investment is:

In the problem, the initial value is $15,500 while the final value is $12,500.
Plugging these data into the formula above, we get:

Then, simplify.

Answer:
The total return on Jill's investment is -19.4%.
Five factors that should be controlled are the dose of the medicine, the time the patients take this medicine, their diet, the stage of this disease and medicine composition.
<h3>Why should some factors be controlled?</h3>
This is done to avoid bias or imprecise results.
<h3>What factors should be controlled?</h3>
Factors related to the medicine itself and factors that can affect the results should be controlled. This includes:
- The dose given to the patients.
- The stage of the disease that should be similar for all patients.
- The medicine compositon and manufacturer.
- The number of day patients take the medicine.
- The patients' diet.
Learn more about medicine in:brainly.com/question/21486381
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We need to construct the system of equations in order to solve that problem. Let's denote one-time membership fee with x and monthly fee with y. Then we can write that John paid x+6y=325 and Abigail paid x+9y=475. Solving the system of equations

, we find that x=25 and y=50. The monthly fee is 50 dollars.
Answer:
1) (2x + 2)(x + 2)
2) 2(x + 1)(x - 1)
3) (x^2 + 3)(x^2 - 3)
4) 2x(x + 5)(x - 2)
5) (5x + 2y)(5x - 2y)
Step-by-step explanation:
1)
2x^2 + 6x + 4
= 2x^2 + 4x + 2x + 4
= 2x(x + 2) + 2(x + 2)
= (2x + 2)(x + 2)
2)
2x^2 - 2
= 2(x^ 2 - 1) (The difference of two squares)
= 2(x + 1)(x - 1)
3)
x^4 - 9 (The difference of two squares)
=(x^2 + 3)(x^2 - 3)
4)
2x^3 + 6x^2 - 20x
= 2x(x^2 + 3x - 10)
= 2x(x + 5)(x - 2)
5)
25x^2 - 4y^2 (The difference of two squares)
= (5x + 2y)(5x - 2y)
Answer:
its domain
Step-by-step explanation: