Lightbulbs act as resistors. Janine is building a circuit that contains two lightbulbs in parallel. One of the lightbulbs has a
resistance of 120 ohms, but the resistance of the second lightbulb is unknown. She models the total
resistance in the
circuit, t, with this equation, in which r represents the resistance of the second lightbulb.
t =
1207
+ 120
Find the inverse of Janine's equation.