1. 1/3 * 3 is equal to 1. Is that what your program is telling you?
2. Accept user input of numbers to represent x and y. Then apply them to the formulas.

>>I am new in java and some basic help would be appreciated. e.g
Ok lets see...

>>1-What's the out put of;
>>double number = (1/3)*3;
>>System.out.println("(1/3)*3 is equal to " + number);
>>What's missing?
Did you try this out on a compiler ? Is this a H.W question ?
Here is a hint : in programming , 1/3 != 0.333...

>>2- Convert each of the following mathematical formula to java >>expression;

>>3x and 3x+y
More hints :
Declare a variable x ;
Declare a variable result1 and result2 and a variable y
For result1 make it equal to 3 time the variable x
For result2 make it equal to result1 plus 3

>>Thank you in advance
Hope that helped. Next time show some effort.

How can I make this to continue until the user presses N? I've tried using while(1), while( option == 'y' || option == 'Y') but it kept giving an error ...