Write the coefficient of :
`4xy` in `x^(2) - 4xy + y^(2)`

Answer

To find the coefficient of \(4xy\) in the expression \(x^2 - 4xy + y^2\), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the expression**: We start with the expression \(x^2 - 4xy + y^2\).

2. **Locate the term of interest**: We need to find the coefficient of the term \(4xy\) in the expression.

3. **Break down the expression**: The expression consists of three terms:
- \(x^2\)
- \(-4xy\)
- \(y^2\)

4. **Focus on the relevant term**: The term that contains \(4xy\) is \(-4xy\).

5. **Extract the coefficient**: The coefficient of the term \(-4xy\) is \(-4\).

6. **Relate it to \(4xy\)**: Since we are interested in the coefficient of \(4xy\), we can express \(-4xy\) as \(-1 \cdot 4xy\). Thus, the coefficient of \(4xy\) in the expression is \(-1\).

### Final Answer:
The coefficient of \(4xy\) in the expression \(x^2 - 4xy + y^2\) is \(-1\).

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