3 is true. Break into like parts. 18/9 is two X to the 4 plus x squared is x to the 6 Y plus y to the 4 is y to the 5 Z to the negative 2 is shown as z This means everything is correct.
I am not sure but I think 4 is true. All numbers are positive. Odd numbers and even numbers do not cross (empty set then). This is based off the fact of odd and even numbers are just odd and even.
