Answer: The length of the candle was 13.5 inches before it was lit.
Step-by-step explanation:
Let the length of candle in the beginning be c.
Constant rate of change in length of candle= -1.6 inches per hour
Since rate of change is constant so the length of candle can be represented by a linear function [Linear function has constant rate of change.]
Linear function : f(x)= mx+c , where x= independent variable.
m= constant rate of change and c= initial value of function.
Let x = Number of hours after the candle was lit.
Put m= -1.6 , x= 3 and f(x)= 8.7 , we get
[tex]8.7=-1.6(3)+c\\\\ 8.7= -4.8+c\\\\ c=8.7+4.8=13.5[/tex]
Hence, the length of the candle was 13.5 inches before it was lit.
