Answer:
5 nights
Step-by-step explanation:
Let x represent the number of nights. She can spend up to and including 500; this gives us the inequality
60x+150 ≤ 500
Subtract 150 from each side:
60x+150-150 ≤ 500-150
60x ≤ 350
Divide both sides by 60:
60x/60 ≤ 350/60
x ≤ 5.83
Since she cannot stay just a portion of a night, she can stay up to 5 nights.