Respuesta :
The correct answer is B.
+ 15 represents the 15 miles she already ran.
30x represents the amount of miles she will need to run each day (because there are 31 days in January, and 1 of them has already been accounted for.
The correct answer is B. She has already ran 15 miles on her first day, which is shown in answers B and D by the (+ 15). There are 31 days in January but since she already did one day, 31 minus 1 which gives 30 and tells us the answer is B