... c tính nh sau ( )()()()nLM LMLMnL LLMLMn21n21=+++=+++= ()()()()nnLDLDLDnLLLDLD 2 2n21n21σ=+++=+++= Theo nh lý gii hn ... 'K5&5 2 L )K5 2 L #&7+75 2 +#+/,)L F)*' 2 +/5&5+#5*777• P#5 2 L &0L ... )48R 2) -8&+#,#,+/"#35) 2 +/7& 2 +/7'/)*)F+#&+##+%&"#5&'"+" 2 )?#,+/35)'+"6& 2) 77##,%"#)*,!)*&+"88/ 2 8+"8.*#,)*,*,5+')*+%#,+/"#8/+")'6& 2) ')*77#"#.0')*70+"8P#.* 2 +/77+"8/7#,+/'+%'+"+"6& 2) 77#"#,'+%5 2+ X 2 M )48R 2) 7)^)F%#,+/57)#5+%87'.+%7)* 2 +/5+#")&5&?/ 2 +/7.+%6#6&8/)#'.)*.+%8-5+#)#''#.* 2 +/75&?)+#5+#.&+.+./+#+"+"5+#85&+#+%8++" 2) '.+%6#+#5&?)6& 2) .5+#)+"/6+.+%5K)8/#6& 2) '#.*'/'#&& 2 *+#50/&5K,#+"6&&+.+%6#+"/')*)#'38'#.*,)*&+.+%85+.0+"5+#,/.+%5+#30.5 2 ...