Answer:
Step-by-step explanation:
1) -3
2) 2
3) you need a graphing tool or some graph paper
Let t = number of hours
The first candle starts at 8 inches.
It burns at 7/10 inch per hour, so in t hours it burns (7/10)t inches.
After t hours, its length is 8 - (7/10)t
The second candle starts at 6 inches.
It burns at 1/5 inch per hour, so in t hours it burns (1/5)t inches.
After t hours, its length is 6 - (1/5)t
You want the lengths to be equal, so the equation is
8 - (7/10)t = 6 - (1/5)t