Suppose that the water level of a river is 34 feet after 3 days of rain and 62 feet after 10 days of rain. The river was 22 feet before the rain began.

What is the rate of change for this scenario? Response area

What is the y-intercept for this scenario? Response area

Write an equation in Point-slope form. Response area

Change that equation to Standard form. Response area

The option "(0, 22)" (5 of 13) has been selected. Press tab to choose a response area, and spacebar to insert it. Press escape to cancel.

Answer: 4, 1/4, 12, (0, 0), (0, 22), (3, 34), (10, 62), (y - 34) = 4(x + 3), (y - 10) = 1/4 (x - 62), (y - 62) = 4(x - 10), 4x - y = -22, 3x + 34y = 22, 10x - 62y = 22

1 answer

To analyze the river's water level during the rain, let's break down the provided information step-by-step.

  1. Calculate the rate of change: The rate of change can be determined by finding the change in water level over the change in days.

    • Water level after 3 days = 34 feet
    • Water level after 10 days = 62 feet
    • Change in water level = 62 - 34 = 28 feet
    • Change in time = 10 - 3 = 7 days

    Rate of change = Change in water level / Change in time = 28 feet / 7 days = 4 feet per day.

    Answer: Rate of change = 4 feet per day.

  2. Find the y-intercept: The y-intercept occurs when time (x) is 0 (before the rain starts). It is given as 22 feet. Thus, the y-intercept is:

    Answer: y-intercept = (0, 22).

  3. Write an equation in Point-slope form: Using the point (3, 34) and the rate of change (slope) of 4, we use the point-slope form of a linear equation, which is: \( y - y_1 = m(x - x_1) \) where \( (x_1, y_1) \) is a point on the line and \( m \) is the slope.

    Using (3, 34): \( y - 34 = 4(x - 3) \).

    Answer: \( y - 34 = 4(x - 3) \).

  4. Change that equation to Standard form: From the point-slope form, we rearrange \( y - 34 = 4(x - 3) \): \[ y - 34 = 4x - 12 \] \[ y = 4x + 22 \] Rearranging to standard form \( Ax + By = C \) gives: \[ -4x + y = 22 \quad \Rightarrow \quad 4x - y = -22. \]

    Answer: \( 4x - y = -22 \).

To summarize:

  • Rate of change: 4 feet per day.
  • Y-intercept: (0, 22).
  • Point-slope form: \( y - 34 = 4(x - 3) \).
  • Standard form: \( 4x - y = -22 \).