Answer:
(0,3)?
Step-by-step explanation:
For this case we must find the solutions of the following quadratic equation:
![2x ^ 2-2x-9 = 0](https://tex.z-dn.net/?f=2x%20%5E%202-2x-9%20%3D%200)
The roots will come from:
![x = \frac {-b \pm \sqrt {b ^ 2-4 (a) (c)}} {2a}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%20%7B-b%20%5Cpm%20%5Csqrt%20%7Bb%20%5E%202-4%20%28a%29%20%28c%29%7D%7D%20%7B2a%7D)
Where:
![a = 2\\b = -2\\c = -9](https://tex.z-dn.net/?f=a%20%3D%202%5C%5Cb%20%3D%20-2%5C%5Cc%20%3D%20-9)
Substituting:
![x = \frac {- (- 2) \pm \sqrt {(- 2) ^ 2-4 (2) (- 9)}} {2 (2)}\\x = \frac {2 \pm \sqrt {4 + 72}} {2 (2)}\\x = \frac {2 \pm \sqrt {76}} {4}\\x = \frac {2 \pm \sqrt {2 ^ 2 * 19}} {4}\\x = \frac {2 \pm2 \sqrt {19}} {4}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%20%7B-%20%28-%202%29%20%5Cpm%20%5Csqrt%20%7B%28-%202%29%20%5E%202-4%20%282%29%20%28-%209%29%7D%7D%20%7B2%20%282%29%7D%5C%5Cx%20%3D%20%5Cfrac%20%7B2%20%5Cpm%20%5Csqrt%20%7B4%20%2B%2072%7D%7D%20%7B2%20%282%29%7D%5C%5Cx%20%3D%20%5Cfrac%20%7B2%20%5Cpm%20%5Csqrt%20%7B76%7D%7D%20%7B4%7D%5C%5Cx%20%3D%20%5Cfrac%20%7B2%20%5Cpm%20%5Csqrt%20%7B2%20%5E%202%20%2A%2019%7D%7D%20%7B4%7D%5C%5Cx%20%3D%20%5Cfrac%20%7B2%20%5Cpm2%20%5Csqrt%20%7B19%7D%7D%20%7B4%7D)
The roots are:
![x_ {1} = \frac {2 + 2 \sqrt {19}} {4} = \frac {1+ \sqrt {19}} {2}\\x_ {2} = \frac {2-2 \sqrt {19}} {4} = \frac {1- \sqrt {19}} {2}](https://tex.z-dn.net/?f=x_%20%7B1%7D%20%3D%20%5Cfrac%20%7B2%20%2B%202%20%5Csqrt%20%7B19%7D%7D%20%7B4%7D%20%3D%20%5Cfrac%20%7B1%2B%20%5Csqrt%20%7B19%7D%7D%20%7B2%7D%5C%5Cx_%20%7B2%7D%20%3D%20%5Cfrac%20%7B2-2%20%5Csqrt%20%7B19%7D%7D%20%7B4%7D%20%3D%20%5Cfrac%20%7B1-%20%5Csqrt%20%7B19%7D%7D%20%7B2%7D)
Answer:
Option C
Answer:
40/6= 6.6667(20/3)
Step-by-step explanation:
I divided the number of days into 6.