Question

Owners of a recreation area are filling a small pond with water. Let y represent the total amount of water in the pond (in liters). Let x represent the total numberof minutes that water has been added. Suppose that x and y are related by the equation y = 700 +31x.Answer the questions below.Note that a change can be an increase or a decrease.For an increase, use a positive number. For a decrease, use a negative number.What was the starting amount of water in the pond?___ litersWhat is the change per minute in the amount of water in the pond?___ liters

Answer 1

Solution

Step 1:

y = 700 + 3x

y represents the total amount of water in the pond (in liters)

x represents the total number of minutes that water has been added

Step 2:

What was the starting amount of water in the pond?

Starting amount of water is when x = 0 minute

$\begin{gathered} y\text{ = 700 + 31x} \\ y\text{ = 700 + 31}\times\text{ 0} \\ \text{y = 700 liters} \end{gathered}$

Step 3:

What is the change per minute in the amount of water in the pond?

Change per minute in the amount of water in the pond = 31

Final answer

What was the starting amount of water in the pond?

700 liters

What is the change per minute in the amount of water in the pond?

31 liters