Đề bài

Tìm:

a) $\int {\left( {3\sqrt x  + \frac{1}{{\sqrt[3]{x}}}} \right)} dx$;

b) $\int {\sqrt x \left( {7{x^2} - 3} \right)} dx\left( {x > 0} \right)$;

c) $\int {\frac{{{{\left( {2x + 1} \right)}^2}}}{{{x^2}}}} dx$;

d) $\int {\left( {{2^x} + \frac{3}{{{x^2}}}} \right)} dx$.