whats the properties for the following
1. ab=1ab
2. [5+(-2)]+-4=5+[-2+(-4)]
3. if 5+4=9 then 9=5+4
4. 3x(2y)=2y(3x)
5. x/2 * 0 = 0
6. x +(y+z)=(x+y)+z
7. (2+14)+1=1+(2+14)
8. (a+5b)+2c=a+(5b+2c)
9. if a = 3 and b = 3 then a = b
10. 3/4a + -3/4a = 0
11. (3*4)25=3(4*25)
12. (1.5x)y=1.5(xy)
13. (x+y)+0=x+y
14. x+y=X+y
15. 6x^2 + x = x (6x + 1)
16. (1/2x) 8 = 8 (1/2x)
17. (1 2/7) (7/9) = 1