Final answer:
The equation of the line representing the river is y = 1/3x - 2. The slope of the line is 1/3, and the y-intercept is -2.
Step-by-step explanation:
The equation of the line representing the river is y = 1/3x - 2. This equation is in slope-intercept form, y = mx + b, where m represents the slope of the line and b represents the y-intercept. In this equation, the slope is 1/3 and the y-intercept is -2.
The slope of 1/3 means that for every 1 unit increase in the x-coordinate, the y-coordinate increases by 1/3. The negative y-intercept of -2 indicates that the line crosses the y-axis at the point (0, -2).
Using this equation, you can determine the y-coordinate of any point on the line by substituting the x-coordinate into the equation and solving for y.