Answer:
D. $145
Explanation:
In order to find out the answer to the equation 100 + 15w = ? we have to multiply 15 by the 3 weeks the student has saved up 15 dollars to get the total money they have saved by saving 15 dollars per week:
15 * 3 = 45
we then add the 100 dollars that was already saved up to 45
100 + 45 = $145
So after 3 weeks $145 have been saved up
Hope this helps!!!