Answer: The expression shows the number of dollars he will have saved by the end of the year is given by

Explanation:
Since we have given that
Amount he saved per month over the first 7 months = $35
Amount he saved per month over the next 5 months = $40
So, total saving by the end of the year is given by

Hence, the expression shows the number of dollars he will have saved by the end of the year is given by
