Замена 7 - x^3 = y; dy = -3x^2 dx; x^2 dx = -1/3*dy
[m]-\frac{1}{3} \int \frac{dy}{\sqrt[6]{y}} = -\frac{1}{3} \int y^{-1/6}dy = -\frac{1}{3} \frac{y^{-1/6+1}}{-1/6+1} + C = -\frac{1}{3} \cdot \frac{6}{5} y^{5/6}+C=[/m]
[m]-\frac{2}{5} (7-x^3)^{5/6}+C[/m]