Answer:
Step-by-step explanation:To determine the interval of movies watched for which Plan A is cheaper than Plan B, let's first write equations for each situation.
For Plan A, the monthly cost can be represented by AA. We know that Plan A costs $8 per month plus $2.50 per movie watched. So, the equation for Plan A is:
AA = 8 + 2.50x
where x represents the number of movies watched per month.
For Plan B, the monthly cost can be represented by BB. We know that Plan B costs $20 per month plus $1.50 per movie watched. So, the equation for Plan B is:
BB = 20 + 1.50x
Now, we need to find the interval of movies watched, x, for which Plan A is cheaper than Plan B.
To do this, we need to compare the costs of Plan A and Plan B. We can set up an inequality to represent this comparison:
AA < BB
Substituting the equations for AA and BB, we have:
8 + 2.50x < 20 + 1.50x
Simplifying the inequality, we get:
2.50x - 1.50x < 20 - 8
1x < 12
x < 12
Therefore, the interval of movies watched, x, for which Plan A is cheaper than Plan B is x < 12.
In other words, if Lucy watches fewer than 12 movies per month, Plan A will be cheaper for her compared to Plan B. If she watches 12 or more movies per month, Plan B will be cheaper.