(1)如果 (A,B)=1,那么[A,B]= (2)如果[M,N]=MN,那么(M,N)= (3)如果(A,B)=A,那么[A,B]= (4)如果[M,N]=N,那么(M,N)= .
:8=18÷ = %==0.375.
:8==0.25= %=5÷ .
÷15=3: =12/ =0.6= %
=20× =12÷15= %= 折= (填小数)= (填成数)
0.375= : == %.