Sum of Radicals
Two radicals can be added only if their indexes and radicands are equal.
For example, these two radicals cannot be added:
![\sqrt[]{a}+\sqrt[3]{a}](https://img.qammunity.org/2023/formulas/mathematics/college/4vwyl7rnse7j4u9p4gg65jr32qoags17j7.png)
Because they don't have the same index even though they have the same radicand.
We have the sum of:
![2\sqrt[]{6}+6\sqrt[]{6}](https://img.qammunity.org/2023/formulas/mathematics/college/worf917lnzhv3cmazpkrzb1uk7ufym9zlk.png)
The radicands and indexes are exactly equal, so we can add their coefficients as follows:
![2\sqrt[]{6}+6\sqrt[]{6}=8\sqrt[]{6}](https://img.qammunity.org/2023/formulas/mathematics/college/igcgpb2v7b8rbhk8s7u4zvcuhlsb1xeozg.png)