To add or subtract radicals, the degree and radicand must be the same. For example, \(2\sqrt{3} + 3\sqrt{3} = 5\sqrt{3}\) but \(2\sqrt{2} + 2\sqrt{3}\) cannot be added because they have different radicands.
What is \( 9 \)\( \sqrt{63} \) - \( 9 \)\( \sqrt{7} \)
| 81\( \sqrt{441} \) | |
| 81\( \sqrt{63} \) | |
| 81\( \sqrt{7} \) | |
| 18\( \sqrt{7} \) |