For a science fair project, Felicia measured the height of a candle as it burned. The table shows the linear relationship between the height of the candle and the number of minutes it burned for.

Candle
Time (minutes) Height
(mm)
1 8,000
2 6,000
3 4,000
4 2,000
5 0

Which function can be used to find y, the height of the candle after it has burned for x minutes?