Chapter 8 - Radical Functions - 8.2 Simplifying, Adding, and Subtracting Radicals - 8.2 Exercises - Page 634: 57

Amy was wrong because she combined radicals that are not similar. The given expression is already in its lowest terms, $4\sqrt7 + 10\sqrt[3]{7}$.

Amy was wrong because she combined the radicals together even though the radicals are dissimilar. Since the radicals are not similar, they cannot be combined and therefore is already in lowest terms.