Tính Lim x^2} - 12x + 35} / {25 - 5x}

Chọn D

Ta có: \(\mathop {\lim }\limits_{x \to 5} \frac{{{x^2} - 12x + 35}}{{25 - 5x}} = \mathop {\lim }\limits_{x \to 5} \frac{{\left( {x - 7} \right)\left( {x - 5} \right)}}{{5\left( {5 - x} \right)}} = \mathop {\lim }\limits_{x \to 5} \frac{{ - \left( {x - 7} \right)\left( {5 - x} \right)}}{{5\left( {5 - x} \right)}} = \mathop {\lim }\limits_{x \to 5} \frac{{ - \left( {x - 7} \right)}}{5} = \frac{2}{5}\).