Tính lim x → 1 2 (2x − 1)/( 2x^2 − 3x + 1) .

\(\mathop {\lim }\limits_{x \to \frac{1}{2}} \frac{{2x - 1}}{{2{x^2} - 3x + 1}} = \mathop {\lim }\limits_{x \to \frac{1}{2}} \frac{{2\left( {x - \frac{1}{2}} \right)}}{{2\left( {x - \frac{1}{2}} \right)\left( {x - 1} \right)}} = \mathop {\lim }\limits_{x \to \frac{1}{2}} \frac{1}{{\left( {x - 1} \right)}} =  - 2\)