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\int(7 x+5)^{3} \mathrm{dx}=\int \mathrm{u}^{3} \frac{1}{7} \mathrm{du}=\frac{1}{7} \cdot \frac{1}{4} \mathrm{u}^{4}+\mathrm{C}=\frac{1}{28}(7 x+5)^{4}+\mathrm{C}