 So, again, they can give you mixed radicals, adding subtracting mixed radicals. So you can have something like, let's just stick with 2 square root 8. 2 square root 8. And then let's go minus 5 square root 30. Okay? Now 2 square root 8, we just did this, but it would be 2, 2, 2. Paramount, they come out as singles, there's a 2 waiting for, so it multiplies the 2, becomes 4 square root 2. Minus 32 is 5 2s multiplied together. It's 4 times 8, 4 breaks down to 2, 2, and 8 breaks down to 8, 2, 2, 2. So it becomes 2, 2, 2, 2, 2, 2. Square root means bring out those 2s as a single 2, bring out those 2s as a single 2. So 2 times 2 is 4, it comes out as 4, because those 2 come out as a 2, those 2 come out as a 2. What's waiting for them is a 5, so 4 times 5 is 20, square root 2. Now, because these things are exactly the same, you can combine it like terms. So 4 minus 20, 4 root 2 minus 20 root 2 is just 4 minus 20, 4 of this minus 20, that's the same thing. So it's just become negative 16 square root 2. And that just means it's a negative number. This is not a negative in the exponent where you flip the whole thing, this is just a negative number. Don't get confused, I'm going to say it again, don't get confused between what's in the base and what's in the exponent. This is just a negative number, and that would be the answer to that, because when you get radicals like that, you have to break them down so they're identical radicals for you to be able to combine them, otherwise you can't combine them.