Tích phân \(\int\limits_0^1 {\left( {3x + 1} \right)\left( {x + 3} \right)dx} \) bằng

* Hướng dẫn giải

\(\begin{array}{l}\,\,\,\,\int\limits_0^1 {\left( {3x + 1} \right)\left( {x + 3} \right)dx} \\ = \int\limits_0^1 {\left( {3{x^2} + 10x + 3} \right)dx} \\ = \left. {\left( {{x^3} + 5{x^2} + 3x} \right)} \right|_0^1 = 9\end{array}\)