Question

The function y=-4x + 150 models the

amount of water in a fish tank over time.
y represents the amount of water left in
the tank in gallons. x represents the time
in minutes.
Part A: What does the slope of the
function's graph represent? What does
the y-intercept of the function's graph
represent?
Explain your reasoning.
Part B: After how many minutes will the
tank be empty? Explain your reasoning.

Answer 1

Explanation:

The equation y = -4x + 150 is telling us the gallons of water reaming (y) after x minutes. The -4 slope represents the rate water is leaving the tank. In this case, it is 4 gallons per mijnute. It is negative since it is leaving the tank. The y-intercept, 150, is the water volume at time 0 minutes, the start. If you only filled it with 75 gallons and then left, the equation would be y=-4x + 40. If you accidently left a valve open, the slope would have a greater negative value (e.g., -10). There is also an equation if your boss see the empty tank: Y = 4590x^9 + 15, where Y is yell ferocity and x is the hours worked that day. 15 is the initial attitude at the start of the day.