判断下列方程是否为恰当方程，并且对恰当方程求解：[tex=14.857x1.571]rIQpLz1SwiFaGtXcfCU8vJ4mcgh/yWq253ZDtZ/JVPca4yTOdpDmaZbIs7PUvWY5PBPoeb96T2lXLzSbEyJuiNE3ORqw5K+ul0vD1kYk/2w=[/tex]

设[tex=1.857x1.214]6tCA+vkG+Ay2eLRhm2vJ5w==[/tex]分别是[tex=0.5x0.786]Tg0I1PUwmDJ7uXa9+yiYMA==[/tex]级，[tex=0.5x0.786]ICKY+F5VdoSQrRn/wUUOyw==[/tex]级可逆矩阵，[tex=1.786x1.214]03I9PkHJmSnbkreh85v/Lg==[/tex]分别是[tex=4.571x1.143]7O/dOd7G3G4IUbObMslSXpKFJcbrIfwq+W+cVStc3i4=[/tex]矩阵，证明：[tex=14.857x1.571]U7j2x31JfaiqhUBC5/QOl4YkT4IJhenXyFoOaRCdmHcGMR2+R99gGgCyIpbOcYQ7a1hXOcb/iPhKeTk7xvbM/A==[/tex].

图7-16所示结构的结点荷载列阵为[img=483x265]17a04dfbe6b8ea5.png[/img] 未知类型：{'options': ['[tex=14.857x1.571]mWIsVdxCmHEM70K5peWdxSTZvO2jebGR2FkO3XZAGsI/JWcQGAT40fuWgXHOK73bSOwzKnZbOcEA2gzpGeylhG9NGTSErYAr7hy5y2pzbg9BWI8Nj16MixwUSyd6lNnF[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxTbspPpiyslAY6i3WXjdGRgekUZBSR9/q1SRz2aaCQRq5+hxQOJaxvuxVtkhFjNL1C77/cONqIk6Xjc3/B9zcMfcgsWO0IVPRI8Siy8rC16W[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxc7SgGTRrfyHJ5jSYGmXEsJTFpDauKxeLOmXRS7Sfett7X0l5o+hXyBgZEA/PW1gcxi8adYqKcymB4Wu1a9PSBwTJ2HDpO0szZAw4GFI2Uk6[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxTbspPpiyslAY6i3WXjdGRjSXVdqDOQCP2Xrm6j8ooJ3e6xckm2THAKTnvcVeAdn9MRH8dE5BJ7D+HvWgRN89EvExGd1Oj7rslPcq2Ld5ao4[/tex]'], 'type': 102}

图7-16所示结构的结点荷载列阵为[img=483x265]17a04dfbe6b8ea5.png[/img] 未知类型：{'options': ['[tex=14.857x1.571]mWIsVdxCmHEM70K5peWdxSTZvO2jebGR2FkO3XZAGsI/JWcQGAT40fuWgXHOK73bSOwzKnZbOcEA2gzpGeylhG9NGTSErYAr7hy5y2pzbg9BWI8Nj16MixwUSyd6lNnF[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxTbspPpiyslAY6i3WXjdGRgekUZBSR9/q1SRz2aaCQRq5+hxQOJaxvuxVtkhFjNL1C77/cONqIk6Xjc3/B9zcMfcgsWO0IVPRI8Siy8rC16W[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxc7SgGTRrfyHJ5jSYGmXEsJTFpDauKxeLOmXRS7Sfett7X0l5o+hXyBgZEA/PW1gcxi8adYqKcymB4Wu1a9PSBwTJ2HDpO0szZAw4GFI2Uk6[/tex]', '[tex=13.286x1.571]mWIsVdxCmHEM70K5peWdxTbspPpiyslAY6i3WXjdGRjSXVdqDOQCP2Xrm6j8ooJ3e6xckm2THAKTnvcVeAdn9MRH8dE5BJ7D+HvWgRN89EvExGd1Oj7rslPcq2Ld5ao4[/tex]'], 'type': 102}

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)