Initial (fix) saving = $1,000.
Saving per week (variable saving) = $150.
Given function for total savings after x week, f(x) = 1,000 + 150x.
According to problem x represents number of weeks.
We need to find the total saving after 12 weeks.
In order to find the total savings after 12 weeks, we need to plug x=12 in the given function f(x) = 1,000 + 150x because x represents number of weeks.
Plugging x=12, we get
f(12) = 1,000 + 150(12).
Multiplying 150 by 12, we get 1800.
f(12) = 1,000 + 150(12) = 1,000 +1,800.
Adding 1,000+,1800, we get
=2,800.
Therefore, total saving after 12 week is $2,800.
