$81! 70 + 11 = 81, therefore dan payed $81
Answer:
40
Step-by-step explanation:
10 + 30 = 40 difference
Answer:
117 units cubed.
Step-by-step explanation:
I have attached the work to your problem.
Please see the attachment below.
I hope this helps!
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
C, because 12 squared plus 16 squared equals 544, then you take the square root of