Marco needs to save a minimum of $420 more to buy a smartphone.
Step-by-step explanation:
Cost of a smartphone = $495
Savings = $75
Least amount of money, m that needs to be saved = ?
Additional savings, m = Total - initial savings
m = $495 - $75
m = $420
The inequality equation would be 75 + m ≥ 495
Therefore, Marco needs to save a minimum of $420 more to buy a smartphone.