WILL FAN AND MEDAL

Patti's Pet Palace has an 85 gallon fish tank. When it needs to be cleaned, it can be drained at a rate of 4 gallons per minute. Assuming the tank was full, and x represents the number of minutes the tank has been draining, which of the following functions represents the amount of water in the tank after x minutes?
f(x) = 4x + 85
f(x) = 85 - 4x
f(x) = 4x - 85
f(x) = 85x - 4

Question

WILL FAN AND MEDAL

Patti's Pet Palace has an 85 gallon fish tank. When it needs to be cleaned, it can be drained at a rate of 4 gallons per minute. Assuming the tank was full, and x represents the number of minutes the tank has been draining, which of the following functions represents the amount of water in the tank after x minutes?
f(x) = 4x + 85
f(x) = 85 - 4x
f(x) = 4x - 85
f(x) = 85x - 4

anonymous · Answer

Yes this is very simple, the answer is y=85-4x