利用矩阵的初等行变换将下列矩阵化成行最简形矩阵:[tex=9.857x3.929]075gCzZzsMRb6HYXYk9X9xW5oWuH8UBTFu2y4JmV6xe+Y7WisSlhzwWTPumEL8qvpQ9e6ff50d1AFGlA7XKD3lD344JBG7BwyDh/HNtZiIJDxraznwpQKonEnvTLaJGVJahvqPl75AQIpE44/tShNA==[/tex]

如果[tex=8.857x3.357]mqOKs44jrJgbK/+3e5yEgUUi7iZ9ZN3sN1CvJoEyKEQCisj6syAGP+L5oQZ0LTL+1eNdEv56ubCDwjSlbuYM+aMncZVYztUnO8k5pxnVAM8BaQc0RoWRO+S229Ru4Rjjdz2V3hrtkL7GCZ0P4eL1j22fklRUbk6/Y37GS8eNCvifrU2fZupR7JsN8bNsSzlk[/tex]，则[tex=9.857x3.929]mqOKs44jrJgbK/+3e5yEgc08ec4l5TzwDBap+y3mkljHrdGWgH3VCat5Z1r5Xm+pBiBcBco6daX6sqW70Lv2Brza24rii6IaikgDbZwBjN3GuFy2F+l/QoDRY8THtcyj4prOnBCaWMWk5b7AYudGIfGi3WcYPGm3QOuuWvmQE+em2NcSQjzdTj44HVJt8ICe+iQUQQfC+ZyauhL/TOUfaQ==[/tex] A: 2 B: 4 C: 12 D: 16

若[tex=8.857x3.357]Uyz5s0rmQIddjb5Jc2T/YQrtN3x5ZN9FMGW6yC3xzseiTBqypew7SW9sf0+ImEr8Gb2OxOc7YQnxDUAy/QpPIvpyRkYir8yXfSAvaVVfv9tpEubyVKyvyG1FvqsyObDQVYRa5euYkQmr6Zp5am+qjeoyfm7qtU6E7/m8bxoAtCI=[/tex]，则[tex=9.857x3.929]Uyz5s0rmQIddjb5Jc2T/Yet6pkqm2clWks988tQGMyddjCfgQJZCXqeyBo6TCVQLD+q4ocARe8VDh4eF88bR2uWUDgBmpI7LuOFSX83tpVYXrB/7L1y8UtKr8v2VjCLamW9xuHzuh/LfosKzoixoWMuCwsl97RSleQYwcCfwWoRtFlHMnwklS6da513LincC[/tex][input=type:blank,size:6][/input] . A: 2 B: 4 C: 8 D: 16

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}

以下谓词蕴含式正确的是（）: (∀x) (A(x)→B(x))=>( ∀x)A(x)→(∀x)B(x)|(∀x) (A(x)↔B(x))=>( ∀x)A(x)↔(∀x)B(x)|(∀x)A(x)∨(∀x)B(x)=>( ∀x) (A(x)∨B(x))|(∃x) (A(x)∧B(x))=>(∃x)A(x)∧(∃x)B(x)

以下谓词蕴含式正确的是（）: (?x) (A(x)→B(x))=>( ?x)A(x)→(?x)B(x)|(?x) (A(x)?B(x))=>( ?x)A(x)?(?x)B(x)|(?x)A(x)∨(?x)B(x)=>( ?x) (A(x)∨B(x))|(?x) (A(x)∧B(x))=>(?x)A(x)∧(?x)B(x)

下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($x)A(x) Ù p Û ($x)(A(x) Ù p ) C: (∀x)(A(x)ÚB(x)) Þ (∀x)A(x)Ú( ∀x)B(x) D: ($x)(A(x)ÙB(x)) Þ ($x)A(x)Ù( $x)B(x)

判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)

以下谓词公式中，( )不是逻辑有效式。 A: ($x)(P(x)∧Q(x)) Þ ($x) P(x)∧($x) Q(x) B: ("x)(P(x)∧Q(x)) Þ ("x) P(x)∧("x) Q(x) C: ($x)(P(x)∧Q(x)) Û ($x) P(x)∧($x) Q(x) D: ("x)(P(x)∧Q(x)) Û ("x) P(x)∧("x) Q(x)

以下谓词公式中，( )不是逻辑有效式。 A: ($x) P(x)∨($x) Q(x) Þ ($x)(P(x)∨Q(x)) B: ("x) P(x)∨("x) Q(x) Þ ("x)(P(x)∨Q(x)) C: ($x) P(x)∨($x) Q(x) Û ($x)(P(x)∨Q(x)) D: ("x) P(x)∨("x) Q(x) Û ("x)(P(x)∨Q(x))