Answer:
(45+73) x 3
Step-by-step explanation:
parenthesis comes first in the order of operations (P E M D A S) so anything in the parenthesis has to go first.
Answer: $48
Step by step:
1. 30 packs times 64 dollars is 1920
2. 1920 divided by 40 packs is 48
because if you pay 64 for 40 packs and your trying to figure out how much for 30 packs you will want to set it up like this:
![\frac{40}{64} \times \frac{30}{x}](https://tex.z-dn.net/?f=%5Cfrac%7B40%7D%7B64%7D%20%20%5Ctimes%20%20%5Cfrac%7B30%7D%7Bx%7D%20)
then you will use fishy method Google fish method in math if this doesn't help
Look carefully at the point where the 2 lines intersect. From that point, look straight down to the x-axis; you'll see that the x-value there is 50. Similarly,
starting at the intersection, look straight left to the y-axis; the y-value there is 11.
Thus, the coordinates of the intersection (i. e., the solution) are found in (50,11).
Answer:
Step-by-step explanation: steps explained in attached file
According to the profit equations given, it is found that since the number of days has to be a positive value, hence the viable answer is that they earn the same profit after 3 days, while the nonviable answer is -4.
<h3>What are the profit equations?</h3>
For the first friend, it is:
![P(x) = -x^2 + 5x + 12](https://tex.z-dn.net/?f=P%28x%29%20%3D%20-x%5E2%20%2B%205x%20%2B%2012)
For the second, it is:
.
The system we solve to find when they earn the same profit is given by:
![P(x) = Q(x)](https://tex.z-dn.net/?f=P%28x%29%20%3D%20Q%28x%29)
![-x^2 + 5x + 12 = 6x](https://tex.z-dn.net/?f=-x%5E2%20%2B%205x%20%2B%2012%20%3D%206x)
![x^2 + x - 12 = 0](https://tex.z-dn.net/?f=x%5E2%20%2B%20x%20-%2012%20%3D%200)
Which is a quadratic equation with coefficients a = 1, b = 1, c = -12. Hence:
![\Delta = b^2 - 4ac = 1^2 - 4(1)(-12) = 49](https://tex.z-dn.net/?f=%5CDelta%20%3D%20b%5E2%20-%204ac%20%3D%201%5E2%20-%204%281%29%28-12%29%20%3D%2049)
![x_1 = \frac{-b + \sqrt{\Delta}}{2a} = \frac{-1 + 7}{2} = 3](https://tex.z-dn.net/?f=x_1%20%3D%20%5Cfrac%7B-b%20%2B%20%5Csqrt%7B%5CDelta%7D%7D%7B2a%7D%20%3D%20%5Cfrac%7B-1%20%2B%207%7D%7B2%7D%20%3D%203)
![x_2 = \frac{-b - \sqrt{\Delta}}{2a} = \frac{-1 - 7}{2} = -4](https://tex.z-dn.net/?f=x_2%20%3D%20%5Cfrac%7B-b%20-%20%5Csqrt%7B%5CDelta%7D%7D%7B2a%7D%20%3D%20%5Cfrac%7B-1%20-%207%7D%7B2%7D%20%3D%20-4)
The number of days has to be a positive value, hence the viable answer is that they earn the same profit after 3 days, while the nonviable answer is -4.
More can be learned about a system of equations at brainly.com/question/24342899