5th hour 2-5

Today we learned some math properties. Commutative property of addition; a+b=b+a for an Example 8+9=9+8. Commutative property of multiplication; a x b+b x a Example 13x14+14x13.
Associative property of addition; (a+b)+c=a+(b+c) Example (6+7)+3=6+(7+3). Associative property of multiplication ; (a x b)x c=a x(b x c) Example (9x8)x3=9x(8x3). Identity property of addition; a+0=a Example 9+0=9. Identity property of multiplication; a x 1=a Example 5x1=5.
Inverse property of addition; for every a, there is an additive inverse -a such that a+(-a)=0 Example 9+(-9)=0. Inverse property of multiplication for every a (a=/=0), there is a multiplication inverse 1 over a such that a(1 over a)=1 Example 7x1 over 7 =1. Symmetric property if a=b, then b=a, Example 9x4=36 then 36=4x9. Distributive property a(b=c)=ab+ac Example 1(9+7)=1x9+1x7; a(b-c)=ab-ac Example 2(4-7)=2x4-2x7. Multiplication property of Zero for every real number n,nx0=0 Example 23x0=0. multiplication property of - 1 for every real number n,-1xn=-n Example -1x(-34)=34.