Let us assume
I = \(\int\limits_{0}^{7}\cfrac{\sqrt[3]{\text x}}{\sqrt[3]{\text x}+\sqrt[3]{7-\text x}}d\text x \)....equation 1
By property, we know that
I = \(\int\limits_{0}^{7}\cfrac{\sqrt[3]{7-\text x}}{\sqrt[3]{7-\text x}+\sqrt[4]{\text x}}d\text x \)....equation 2
Adding equation 1 and 2
2I = \(\int\limits_{0}^{7}\cfrac{\sqrt[3]{\text x}}{\sqrt[3]{\text x}+\sqrt[3]{7-\text x}}d\text x \) + \(\int\limits_{0}^{7}\cfrac{\sqrt[3]{7-\text x}}{\sqrt[3]{7-\text x}+\sqrt[4]{\text x}}d\text x \)
We know