False
All functions are relations, but not all relations are functions
The 2nd one is right
112.5 divided by 15 is 7.5
Answer: Y= X+4•2
Word form: Y equals X plus 4 times 2
Answer:
time is Y-axis and gallons is x-axis
Answer:
The coordinate of the wells are
![(-4 -\sqrt[]{\frac{53}{2}}, 70+15\sqrt[]{\frac{53}{2}})](https://tex.z-dn.net/?f=%20%28-4%20-%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D%2C%2070%2B15%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D%29)
![(-4 +\sqrt[]{\frac{53}{2}}, 70-15\sqrt[]{\frac{53}{2}})](https://tex.z-dn.net/?f=%20%28-4%20%2B%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D%2C%2070-15%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D%29)
Step-by-step explanation:
The y coordinate of the stream is given by 
. Also, the y coordinate of the houses are determined by y=-15x+10. We will assume that the houses are goint to be built on the exact position where we build the wells. We want to build the wells at the exat position in which both functions cross each other, so we have the following equation
or equivalently
(by summing 15x and substracting 10 on both sides)
Dividing by 2 on both sides, we get
Recall that given the equation of the form 
the solutions are
![x = \frac{-b \pm \sqrt[]{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=%20x%20%3D%20%5Cfrac%7B-b%20%5Cpm%20%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D)
Taking a =2, b = 16 and c = -21, we get the solutions
![x_1 = -4 -\sqrt[]{\frac{53}{2}}](https://tex.z-dn.net/?f=x_1%20%3D%20-4%20-%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D)
![x_2 = -4 +\sqrt[]{\frac{53}{2}}](https://tex.z-dn.net/?f=x_2%20%3D%20-4%20%2B%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D)
If we replace this values in any of the equations, we get
![y_1 = 70+15\sqrt[]{\frac{53}{2}}](https://tex.z-dn.net/?f=y_1%20%3D%2070%2B15%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D)
![y_2 = 70-15\sqrt[]{\frac{53}{2}}](https://tex.z-dn.net/?f=y_2%20%3D%2070-15%5Csqrt%5B%5D%7B%5Cfrac%7B53%7D%7B2%7D%7D)
