Answer:
second answer: y = 5x + 120; $180
Explanation:
he starts with $120.
so, whatever else he does per month, there will always be the $120 starting amount to be added.
so, the third and the fourth answers are out.
then think : $5 every month.
that is how much after 2 months ? 2×5 = $10.
how much after 3 months ? 3×5 = $15.
so it has to be an equation that contains 5x (5 times the number of months).
combining both thoughts :
y = 5x + 120
now let's use x = 12 (for 12 months = 1 year).
5×12 + 120 = 60 + 120 = $180.
yes, it is that simple. no hidden "hocus pocus" is needed. just common sense.