what are the properties of the following:
1. 7+(8+3)=(7+8)+3
2. 3(4y-3)=12y-9
3. 2x+y=y+2x
4. rw=wr
5. 6+3c=3(2+c)
6. 3*(x*y)=(3*x)*y

are the following numbers Natural num