根据同类项对应项：得：|m-3|=1 ①
1=|4n| ②
互为倒数：得：mn=1 ③
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由①②③解得m=4,n=1/4
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n-mn-3(m/4-4)-(1/4)m-11
=n-mn-3m/4+12-m/4-11
=n-mn-m+1
=（1/4）-1-4+1
=-（15/4 ）