Fill in the blanks and write the property used in each of the following.
`7+[(-5)+(-8)]="______"+(-8)`

Answer

To solve the question, we need to fill in the blank in the expression \( 7 + [(-5) + (-8)] = "______" + (-8) \) and identify the property used.

### Step-by-Step Solution:

1. **Understand the Expression**:
The expression given is \( 7 + [(-5) + (-8)] \). We need to simplify the part inside the brackets first.

2. **Calculate Inside the Brackets**:
\[ (-5) + (-8) = -5 - 8 = -13 \]
So, we can rewrite the expression as:
\[ 7 + (-13) \]

3. **Perform the Addition**:
Now, we add \( 7 \) and \( -13 \):
\[ 7 + (-13) = 7 - 13 = -6 \]

4. **Rewrite the Expression**:
Now we can rewrite the original equation:
\[ -6 = "______" + (-8) \]
To find the blank, we can rearrange the equation:
\[ "______" = -6 + 8 \]

5. **Calculate the Value**:
\[ -6 + 8 = 2 \]
Therefore, the blank can be filled with \( 2 \).

### Final Answer:
The filled expression is:
\[ 7 + [(-5) + (-8)] = 2 + (-8) \]

### Property Used:
The property used here is the **Associative Property of Addition**, which states that the way in which numbers are grouped in addition does not change their sum.