а) \( \int (x^4 (x - 3)^2) dx \)
\[ \int x^4 (x^2 - 6x + 9) dx \]\[ \int (x^6 - 6x^5 + 9x^4) dx \]\[ = \frac{x^7}{7} - 6\frac{x^6}{6} + 9\frac{x^5}{5} + C \]\[ = \frac{x^7}{7} - x^6 + \frac{9}{5}x^5 + C \]б) \( \int \frac{3x^3 + 5x^2 - 1}{x^3} dx \)
\[ \int \left( \frac{3x^3}{x^3} + \frac{5x^2}{x^3} - \frac{1}{x^3} \right) dx \]\[ \int \left( 3 + \frac{5}{x} - x^{-3} \right) dx \]\[ = 3x + 5 \ln|x| - \frac{x^{-3+1}}{-3+1} + C \]\[ = 3x + 5 \ln|x| - \frac{x^{-2}}{-2} + C \]\[ = 3x + 5 \ln|x| + \frac{1}{2x^2} + C \]Ответ: а) \( \frac{x^7}{7} - x^6 + \frac{9}{5}x^5 + C \); б) \( 3x + 5 \ln|x| + \frac{1}{2x^2} + C \).