Cho \(\int\limits_a^b {\lef...

C

- Hướng dẫn giải

\(\int\limits_a^b {\left( {2x - 1} \right)dx = \left( {{x^2} - x} \right)\left| \begin{array}{l}^b\\_a\end{array} \right. = \left( {{b^2} - {a^2}} \right) - \left( {b - a} \right) = 1 \Leftrightarrow {b^2} - {a^2} = b - a + 1.} \)