Where's the graph? Insufficient info here to enable us to answer this question.
If possible take a photo of the original problem and upload the image to Brainly.
Y=|x+7|-9
Im not sure how to explain this sorry
We will study the convergence of the series

For

the series has constant general term which is divergent.
For

the series diverges since its general term goes to infinity as n goes to infinity.
For

, the series converges since it is equivalent to the Riemann series.
March 15 - March 31 = 17 days
April = 30days
May = 31 days
June = 30 days
July = 31 days
August = 31 days
Sept 1 - Sept 15 = 15 days
total = 185 days