Radical expressions can be added in a way that is similar to monomials. Two radical expressions are like radical expressions if their indices and radicands are alike.
 
 | 
Figure 1. | 
|---|
Let's try an example:
 
 | 
Figure 2. | 
|---|
These two expressions can be added because they have the same values in their radicands.
 
 | 
Figure 3. | 
|---|
These two expressions cannot be added in their current form.