The question is a little hard to understand... let me see what i can do. I'll edit what i figure out on here. :) (PS) Did you reword the question? Do you think you could double check and make sure this is what the question looks like?
Started her day with a full bag of apples (?)
She needs 3 for an apple pie
She had 12 total (?)
Or maybe she needs 12 for a pie and now she has 3?
With the given order of integration, the interval over D is

Answer: s = -4
Step-by-step explanation:
s/4 + 15 = 14
We can subtract 15 from both sides:
s/4 = -1
We can multiply both sides by 4:
s = -4