In this video, we are going to add and subtract radical expressions.

We can add $3x+5x=8x$
and we can do the same to $3\sqrt{2}+5\sqrt{2}=8\sqrt{2}$

Since we can only combine like terms, we know that we cannot add $5x$ and $7y$ together
so we cannot add $5\sqrt{2}$ and $7\sqrt{3}$ together either

For $9\sqrt{6}+3\sqrt{5}-4\sqrt{6}+2\sqrt{5}$,
it would be $5\sqrt{6}+5\sqrt{5}$

Let’s look at other examples:
$3\sqrt{2}+6\sqrt{18}$
$3\sqrt{2}$ would stay like itself, while $6\sqrt{18}$ can be broken into $18\sqrt{2}$
Now that both expressions are like terms, they can be combined into $21\sqrt{2}$

$6\sqrt{12}-4\sqrt{45}+2\sqrt{3}-\sqrt{80}$
After simplifying each radical expression, it will be $12\sqrt{3}-12\sqrt{5}+2\sqrt{3}-4\sqrt{5}$
After combining like terms, it will be $14\sqrt{3}-16\sqrt{5}$