Simplify each expression.
$\frac{x-7}{7-x}$

• A. $-x$
• B. $-1$
• C. $x$
• D. $\frac{7}{x-7}$

Answer: (B)

Verified step by step guidance

1. Start with the given expression: \(\frac{x-7}{7-x}\).
2. Notice that the denominator \(7 - x\) can be rewritten by factoring out a negative sign: \(7 - x = -(x - 7)\).
3. Substitute this back into the expression to get \(\frac{x-7}{-(x-7)}\).
4. Since \(x - 7\) appears in both numerator and denominator, they cancel out, leaving \(\frac{1}{-1}\) or simply \(-1\).
5. Therefore, the simplified form of the expression is \(-1\).