Tính \(\mathop {\lim }\limits_{x \to 6} \frac{{{x^...

Câu hỏi: Tính \(\mathop {\lim }\limits_{x \to 6} \frac{{{x^2} - 9x + 18}}{{42 - 7x}}\).

A. \( - \frac{3}{7}\)

B. \( - \infty \)

C. \(  \frac{3}{7}\)

D. \( + \infty \)