The operation " $\odot$ " is defined as: $a \odot b=a \times b-(a+b)$, please calculate: $6 \odot(5 \odot 4)=$
【Analysis and Solution】
Define new operation.
(Method one)
$6 \odot(5 \odot 4)=6 \odot[5 \times 4-(5+4)]=6 \odot 11=6 \times 11-(6+11)=49$
(Method two)
$a \odot b=a \times b-(a+b)=(a-1) \times(b-1)-1$
$6 \odot(5 \odot 4)=6 \odot[(5-1) \times(4-1)-1]=6 \odot 11=(6-1) \times(11-1)-1=49$