To address the problem step by step, we need to analyze the information given.
Given Data:
- Water Level at Day 3: 45 feet
- Water Level at Day 10: 10 feet
- Initial Water Level (Before Drought): 60 feet
a. Rate of Change (Slope)
The slope or rate of change can be calculated using the formula:
\[ \text{slope} = \frac{y_2 - y_1}{x_2 - x_1} \]
Let (x₁, y₁) = (3, 45) and (x₂, y₂) = (10, 10):
\[ \text{slope} = \frac{10 - 45}{10 - 3} = \frac{-35}{7} = -5 \]
The rate of change (slope) is -5.
b. Y-Intercept
The y-intercept occurs when x = 0. The river's initial level before the drought began was 60 feet when no time has passed. Thus, the y-intercept is also (0, 60).
c. An Equation in Slope-Intercept Form
Using the slope-intercept form, \(y = mx + b\), we can substitute the slope (-5) and y-intercept (60):
Substituting into the equation:
\[ y = -5x + 60 \]
d. An Equation in Standard Form
To rewrite the equation in standard form \(Ax + By = C\):
Starting from \(y = -5x + 60\):
- Add \(5x\) to both sides:
\[ 5x + y = 60 \]
So the standard form is 5x + y = 60.
Summary of Responses:
- a. Rate of change (slope): -5
- b. Y-Intercept: (0, 60)
- c. Equation in slope-intercept form: \(y = -5x + 60\)
- d. Equation in standard form: \(5x + y = 60\)
If you have further questions or need clarifications on other parts of the scenario, let me know!