This set of radicals can be considered a special case. 

Because 4 is a perfect square and 6 cannot be simplified any further, solve by taking the square root of 4:

This means the final answer is 

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

Both radicals are completely simplified, but their bases are not the same. This means we get a final answer of 

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

Because both of these radicals are perfect squares, this becomes a simple problem.

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

Because both of these radicals are perfect squares, this becomes a simple problem.

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

In order to add, first simplify each radical as follows:

Since the radicals are the same, treat them like variables and add the "coefficients" in from of them to solve.

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

In order to add, first simplify the first radical as follows:

Since the radicals are the same, treat them like variables and add the "coefficients" in from of them to solve.

In order to add or subtract, first simplify each radical completely. If the remaining number under the square root sign is the same for both numbers they can be added- much like with variables.

For this problem, it goes as follows:

In order to add, first simplify the second radical as follows:

Since the radicals are the same, treat them like variables and add the "coefficients" in from of them to solve.

Step 1: Break down all numbers inside the radicals into perfect squares and other numbers:

Step 2: Re-write the double of numbers outside, and the single repeated numbers inside the square root.

Step 3: Write the radicals in terms of the original function:

Step 4: Combine like terms:

The first two terms are already in simplified form because the number in the radical cannot be broken down into numbers that have pairs.

We will only need to break down the last term...

We then replace  in the original equation with what we just calculated:

Add common terms, and then we have our final answer...