How are the graphs of the functions f(x) = and g(x) = related?

The x variable, that is being multiplied.

Red candle:
Initial height  = 8 in
Burn rate = 710 in/h
After x hours, the height will be
h₁ = 8 - 710x

Blue candle:
Initial height = 6 in
Burn rate = 15 in/h
After x hours, the height will be
h₂ = 6 - 15x

When the two heights are equal, then
h₁ = h₂
8 - 710x = 6 - 15x
-695x = -2
x = 0.00288 hours


The answer may take one of these forms:
0.003 hours, or
0.0029 hours, or
0.00288 hours.