can someone help me solve this?

Question

anonymous · Answer

Post your question and we will help

anonymous · Answer

$$3\sqrt{2x}+x \sqrt{8x}-5\sqrt{18x}$$

anonymous · Answer

can you help walk me through it?

anonymous · Answer

Pls wait there is a bit of mistake.

anonymous · Answer

ok

amistre64 · Answer

if we let u = sqrt(2x)

$$3\sqrt{2x}+x \sqrt{8x}-5\sqrt{18x}$$
$$3u+x \sqrt{4}~{u}-5\sqrt{9}~{u}$$

anonymous · Answer

im working on adding and subtracting radial expressions . that doesnt seem right

anonymous · Answer

$$3\sqrt{2x}+x \sqrt{8x} -5\sqrt{18x}=3\sqrt{2x}+x \sqrt{4\times 2x} -5\sqrt{9\times 2x}$$
$$=3\sqrt{2x}+2x \sqrt{2x} -15\sqrt{2x}  =2x \sqrt{2x} -12\sqrt{2x}   $$
This is the simplified form of the given problem.

anonymous · Answer

if you dont mind me asking, how did you get that?

anonymous · Answer

$$3\sqrt{2x}+x \sqrt{8x}-5\sqrt{18x}$$
If you are wondering how this was done, there are a few things you need to know. 
(1)You need to know the index of the radical.
(2)You need to know the radicand of the radical.
(3)You need to know what a perfect square looks like.
(4)You need to know how to simplify a radical
(5)You need to know when you can use the Distributive Property with radicals to add or subtract radicals.

(1) What is the index of the radical $ \sqrt[3]{8}$? The index is the number 3
(2) What is the radicand of the radical $ \sqrt[3]{8}$? The radicand is the number 8,which is and always under the radical sign.
(3) A perfect square can be squared such as $ \sqrt{4} =2$  $ \sqrt{16} =4$
(4)To simplify a radical, we have to write the radicand as the product of a perfect square and a factor that does not have a perfect square. 

For instance $ \sqrt{48} $ can be broken down as  a product of a perfect square and a factor that is not a perfect square. We would break this down like $ \sqrt{16} * \sqrt{3} $  The $ \sqrt{16}$ is the perfect square and $ \sqrt{3} $  is our square that is not perfect.

Now we square $ \sqrt{16} = 4  $ and  take the 4 and place it like so $ 4\sqrt{3} $ with our radical that is not perfect. Now  $ \sqrt{48} $ is simplified to $ 4\sqrt{3} $

(5) The only time you can add or subtract and use the Distributive Property in order to add and subtract is when the radical has the same index and the same radicand. Right now all radicals in$ 3\sqrt{2x}+x \sqrt{8x}-5\sqrt{18x} $ has the same index but they do not have the same radicand. To solve this we have to simplify the radicals that can be simplified and see if we can get the same radicand for all three radicals. We simplify like in step 4. 

Once you have all the radicals in their simplest form, you can use the Distributive Property to add them or subtract them as long as they have the same index and radicand.

If you want to see it done step by step, let us know.