Answer:
y = 4x + 9 
Explanation:
okay so you already know that the tank started with 9L of water making it the y-intercept
so you need to find the slope
41-17/8-2 = 24/6 = 4 
so the slope is 4
if you put all of that information together, the equation is going to look like this: 
y = 4x + 9