Answer:
150 and -150
Explanation:
For question number 2...
You started off with an energy level of 250 and something was added to make it 400.
To figure out what this "something" was, you simply subtract the numbers.
400 - 250 = 150
For question number 3...
You start off with 325 and end with 175. Here, the outcome is smaller or less than what you started with. So, you know that you took away a certain amount of energy. To figure that out, you again subtract.
325 - 175 = 150
To make the equation make sense, you would subtract 150.
So the answer would -150.