Since eleven is odd, there must be a centra element, which in this case is the sixth. So, we can write 11 consecutive integers as

Since the arithmetic mean is the sum of the values, divided by how many they are, we have

So, the mean of 11 consecutive integers is the 6th integer.
I'm assuming this is a system of equations you want solved so,
x = -y + 3
-2(-y+3)+4y = 6
2y - 6 + 4y = 6
6y = 12
y = 2
x + 2 = 3
x = -1
(-1,2)
The original bill is $ 83.475
Answer:
I believe she spent $150 for the first three months.
The hidden question i think is how many minutes did gloria spend in total OR how many packages did gloria need to buy. sorry i haven't done hidden questions in a long time.
Answer: I am going to put a link
maybe its going to help you?
Step-by-step explanation:
http://s3.amazonaws.com/illustrativemathematics/illustration_pdfs/000/001/217/original/illustrative_mathematics_1217.pdf?1390751150