Need help with detailed answers to this questions about java
1- Write a method code defined by yourself for the sum of 3 numbers and that outputs the value. Write only the code of the Method.
2- Mention and explain 2 Methods predefined. Give an example of how you an use them?
3- What's the use of the variable "CLASSPATH"? Explain in your own words
4- What is the code "extends" used for? Explain giving an example