1) when the Bryant’s leave town for a vacation, they put their dog Tyco in a kennel. The kennel charges $15 for an immediate flea bath and $5 per day.

A.) write and equation in slope intercept form to represent the situation.
B.) graph the equation.
C.) explain why only one quadrant is needed to graph this situation.

1 answer

Let's break down the problem step by step:

A.) Write an equation in slope-intercept form.

To represent the costs associated with putting Tyco in the kennel, we can define the variables:

  • Let \( y \) be the total cost in dollars.
  • Let \( x \) be the number of days Tyco stays at the kennel.

The kennel charges a one-time fee of $15 for the flea bath, and they also charge $5 per day.

The total cost can be expressed as:

\[ y = mx + b \]

Where:

  • \( m \) is the slope (the cost per day)
  • \( b \) is the y-intercept (the initial cost)

In this case:

  • The slope \( m = 5 \) (the daily charge)
  • The y-intercept \( b = 15 \) (the initial fee for the flea bath)

So, the equation representing the total cost is:

\[ y = 5x + 15 \]

B.) Graph the equation.

To graph the equation \( y = 5x + 15 \):

  1. Start with the y-intercept at \( b = 15 \). This means your graph will start at the point (0, 15) on the y-axis.
  2. The slope is \( 5 \), which means for every day (1 unit increase in \( x \)), the cost increases by $5 (1 unit increase in \( y \)). So from (0, 15), if \( x = 1 \), then \( y = 5(1) + 15 = 20 \). Plot the point (1, 20).
  3. Continuing this, if \( x = 2 \), then \( y = 5(2) + 15 = 25 \). Plot the point (2, 25).
  4. Draw a straight line through these points extending to the appropriate range of \( x \).

C.) Explain why only one quadrant is needed to graph this situation.

This situation only needs the first quadrant (Quadrant I) because:

  • In this scenario, both variables \( x \) (number of days) and \( y \) (total cost) must be non-negative.
  • The number of days \( x \) cannot be negative (you can't have a negative number of days).
  • The total cost \( y \) cannot be negative (costs are always non-negative).

Therefore, both \( x \) and \( y \) will always be zero or positive, which confines the graph to the first quadrant where \( x \geq 0 \) and \( y \geq 0 \).