Answer:
Manuel can't go on a trip this fall because twenty-five dollars aren't enough to buy gas for the trip.
Step-by-step explanation:
According to the subject-verb agreement, the subject and verb must agree in number.
The sentence Manuel can't go on a trip this fall because twenty-five dollars aren't enough to buy gas for the trip. is incorrect, as singular verbs should be used with specific amounts of money, even if plural words or symbols for currency are present. This is what this sentence would look like corrected:
Manuel can't go on a trip this fall because twenty-five dollars isn't enough to buy gas for the trip.
Another example of this rule: Today, $5,000 was raised for the local animal shelter. (Instead of $5,000 were…)