Answer: A. There were 500 liters in the tank when the leak started, and it is decreasing by 9 liters per minute.
Step-by-step explanation:
This equation is in the form; y =mx + c.
<em>c</em> in this equation is the value of y when x is at 0.
<em>c</em> in the above formula is 500 which means that the number of litres (y) at zero minutes(x) is 500 litres.
<em>m</em> is the rate of change as a result of a change in x.
<em>m</em> in this equation is -9 which means that the water is reducing by 9 litres every minute (x).