AlgebraMediumMeaning of the x-intercept in context
Algebra practice question
The function p(t) = 220 − 4t models the number of litres of fuel in a generator's tank t hours after it is switched on. What does the value 55 represent in this context, given that p(55) = 0?
- A. The number of hours until the tank is emptyCorrect
- B. The number of litres the tank held at the start
- C. The number of litres used each hour
- D. The number of litres left after one hour
Answer: A. The number of hours until the tank is empty
p(55) = 0 means that after 55 hours there is no fuel left: the tank empties at 55 hours.
Why the other answers are wrong
- B. The number of litres the tank held at the start
- The starting amount is p(0) = 220 litres.
- C. The number of litres used each hour
- The hourly use is the slope's size, 4 litres.
- D. The number of litres left after one hour
- After one hour there are 216 litres.
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