Answer:
19. 1/2
20. 0
21. y = 1/2x + 0
Explanation:
The rate of change is 1/2 because to find the slope, or the rate of change, the equation is y/x, or rise over run.
Minutes, or time is the independent variable that is found along the x-axis of a graph, so we can substitute x for 4 minutes.
The amount of water in the pool changes over time, which correlates with the dependent variable, y. Thus, we can substitute 2 feet for y, giving us 2/4 or 1/2.
The initial value, b, is zero because the pool initially starts with no water in it.
The formula for a linear equation is y=mx+b, where m is the slope or rate of change and b is the y-intercept, the value of y at which it crosses the y-axis. Using the numbers from the previous answers, we can plug in our m and b values into the formula. After we plug in the values, you will get y = 1/2x + 0, or y = 1/2x. Hope this helps!