Answer:
The 43rd day of spending $45.
Explanation:
Let the number of days = x.
If she spends $45 per day, then in x days she spends 45x.
She starts with $2400, so 45x is subtracted from 2400.
2400 - 45x < 500
Subtract 2400 from both sides.
-45x < -1900
Divide both sides by -45. Remember to change the direction of the inequality sign when multiplying or dividing by a negative number.
x > 42.2
Answer: The first day is the 43rd day of spending $45.