Final answer:
The linear equation y = (2.0 km/min) x + 0 can be used to represent the candle length after burning x number of minutes.
Step-by-step explanation:
The linear equation that can be used to represent the candle length, y, after burning x number of minutes is y = (2.0 km/min) x + 0.
In this equation, the independent variable is the number of minutes, labeled as x, and the dependent variable is the candle length, labeled as y. The coefficient of x, 2.0 km/min, represents the rate at which the candle burns.