运算定律公式

加法交换律 = Commutative Law of Addition :a + b = b + a
加法结合律 = Associative Law of Addition :
a + b + c = (a + b) + c = a + (b + c)
乘法交换律 = Commutative Law of Multiplication :a×b = b×a
乘法结合律 = Associative Law of Multiplication :
a×b×c = (a×b)×c = a×(b×c)
乘法分配律 = Distributive Law of Multiplication ：
a×(b + c) = a×b + a×c
传递律 = Transitive Law :∵ a = b,b = c,∴ a = c
反身律 = Reflexive Law :a = a