运算规律 (AB)C=A(BC); (AB)=(4)B=A(AB,(其中为数); A B+C)=AB+AC, (B+C)A=BA+CA EmAmxn= Amxn= Amxnen 上页运算规律 (AB)C = A(BC); (AB) = (A)B = A(B), (其 中为 数); ( ) ; ( ) , B C A BA CA A B C AB AC + = + + = + E A A A E . m mn = mn = mn n