When searching for math videos on YouTube, it's important to know the name of the topic you're searching for. If you don't know the name of the topic, look in your notes and the homework assignment to see if the topic is listed there.
When you find the name of the topic, enter it in the search field on YouTube. For example, if you need help with systems of equations, search for "systems of equations":
If you want to see worked-out examples in particular, add the word "examples" to your search:
You will get more accurate results if you make your search more specific. For example, if you're solving systems of equations by substitution, you could do the following search: