若[tex=5.357x1.786]ENxIatiC2yqgaopSQCG83hIqSAjuSZPwn4sgaeByYsIoIoryOA+TvxR4NIRDOb8M[/tex] 和[tex=3.571x1.786]ENxIatiC2yqgaopSQCG83kq7cB9TRy5xQCzGX37ilzU=[/tex]都存在,则 [tex=3.5x1.786]ENxIatiC2yqgaopSQCG83k5pxSu58mt4KVB8LNp1auY=[/tex]也存在.
举一反三
- 判断下列命题的真假,并说明理由:若 [tex=5.357x1.786]ENxIatiC2yqgaopSQCG83hIqSAjuSZPwn4sgaeByYsIoIoryOA+TvxR4NIRDOb8M[/tex] 及 [tex=3.5x1.786]ENxIatiC2yqgaopSQCG83jnIEE6HYlwQCcn45W4zBKQ=[/tex] 都存在，则 [tex=3.5x1.786]eb9EsCxRdElJ8qHK2ualaIKJHBbxpCGi/EhhXlR5B2o=[/tex] 也存在.
- 若[tex=6.5x1.786]ENxIatiC2yqgaopSQCG83qJOnIMmGNvTzpEBsmfIBqJT36ojh2zfC/LjqO/8yeDA[/tex]和[tex=3.5x1.786]ENxIatiC2yqgaopSQCG83jnIEE6HYlwQCcn45W4zBKQ=[/tex]都存在,则[tex=3.5x1.786]ENxIatiC2yqgaopSQCG83uMrRGd+963Yn7ooNooUup8=[/tex]也存在.
- 若[tex=3.5x1.786]ENxIatiC2yqgaopSQCG83jnIEE6HYlwQCcn45W4zBKQ=[/tex]和[tex=3.5x1.786]ENxIatiC2yqgaopSQCG83uMrRGd+963Yn7ooNooUup8=[/tex]都不存在,则[tex=3.786x2.714]ENxIatiC2yqgaopSQCG83pATn6XEVLs4sVtRY0LrDTvdjv+6szwcWhsIGDkHH0Xn[/tex]也不存在.
- 6个顶点11条边的所有非同构的连通的简单非平面图有[tex=2.143x2.429]iP+B62/T05A6ZTM0eeaWiQ==[/tex]个，其中有[tex=2.143x2.429]ndZSw3zT0QTOVLVdoUto1Q==[/tex]个含子图[tex=1.786x1.286]J+vVZa2YaMpc6mJBbqVvWw==[/tex]，有[tex=2.143x2.429]lmhx48evnQMhi03NovPXig==[/tex]个含与[tex=1.214x1.214]kFXZ1uR8GjycbJx+Ts2kyQ==[/tex]同胚的子图。供选择的答案[tex=3.071x1.214]3KinXFh3SXhZ7nIe1y9KEV6aadxhhJWeEy6Dij1iObdMUZkY6ZA5J2dVVjPSuhEf[/tex]：(1) 1 ;(2) 2 ;(3) 3 ; (4) 4 ;(5) 5 ;(6) 6 ; (7) 7 ; (8) 8 。
- 判断下列命题是否为真：（1）[tex=3.643x1.357]/5abqJjwKZ1qr+6hsVFF5EBvfq3ggOFNlHMClz0h9nk=[/tex]（2）[tex=2.929x1.357]rGJpyjIjJpbcoBTWxP0Jiw==[/tex]（3）[tex=4.5x1.357]2wycHMoqU83MyEp17iBils58bR7YLuCTI2G9NVAdlfY=[/tex]（4）[tex=5.214x1.357]CTz2gu+IIm1GgNmYMGaduCRtA41wnW4WqwRWwEhq6aA=[/tex]（5）[tex=4.857x1.357]1DcE2BMMOaZhTuxR/mjgsboXxfg5ET59Dp4I/jjEDuw=[/tex]（6）[tex=4.643x1.357]BSryrsQYOvTP2hTWRu6t4nAuJwlSs4L9jaq70EpB+Us=[/tex]（7）若[tex=6.0x1.357]y0IZLUnBO88nR8WBZYvd7QXv5S1OMINV5cQNzPyiyAc=[/tex]，则[tex=3.429x1.357]1brfPwTkVVIX4GfoMIUskA==[/tex]（8）若[tex=7.643x1.357]MhLfJXZnhbXiB0x3oNtFzThV4Y1mJxe1VYr7PkJE/T6hmTD3WWp+UxbNwvUQ6DHk[/tex]，则[tex=4.143x1.357]LZUA94ISo1po5HWsOVeBCjo0rMvj7uw3bGw5HiZenrI=[/tex]