Answer:
Observe that f(x) is a continuous function when 
because is a polynomial. The possible problem may occur in x=1.
Then, f(x) is discontinuous in x=1 if the limits of f to the right and the left of 1 exist and are different or if some of those limits doesn't exist.
Let's calculate the limits:
Since, 
then f(x) is discontinuous in x=1.
Answer:
Mason has
- 16 20¢ stamps;
- 25 3¢ stamps;
- 40 49¢ stamps.
Step-by-step explanation:
Let x be the number of 20¢ stamps, then the number of 3¢ stamps is x + 9.
Mason has 56 total 49¢ and 20¢ stamps, then the number of 49¢ stamps is 56 - x.
Amounts:
- in 49¢:
cents; - in 20¢:
cents; - in 3¢:
cents.
Total amount:
- $23.55.
Hence,
Mason has
- 16 20¢ stamps;
- 25 3¢ stamps;
- 40 49¢ stamps.
