Final answer:
To calculate the remaining minutes Alexa has to watch her movie, subtract the time watched (40 minutes) from the total movie length (120 minutes), resulting in 80 minutes left.
Step-by-step explanation:
The expression that represents m, the number of minutes Alexa has remaining to watch the movie, is calculated by subtracting the amount of time she has already watched from the total length of the movie. Alexa has watched at most 40 minutes of a movie that is 120 minutes long.
To find the remaining time, we use the expression:
m = 120 - 40
Therefore, the number of minutes Alexa has left to watch the movie is m = 80 minutes.