当X=[ ]时,5X-9=51[2分]

（171）8=( )2

下列不等式中正确的是（ ）． A: [img=171x51]18038697dc36b32.png[/img] B: [img=171x51]18038697e995e6d.png[/img] C: [img=186x51]18038697f2d2d4b.png[/img] D: [img=188x52]18038697fc99c39.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802cf7add98f7c.png[/img] B: [img=171x51]1802cf7aeb31e9d.png[/img] C: [img=186x51]1802cf7af8c2d2a.png[/img] D: [img=188x52]1802cf7b0199b7f.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802cf8c6ed6006.png[/img] B: [img=171x51]1802cf8c7d778ba.png[/img] C: [img=186x51]1802cf8c8849690.png[/img] D: [img=188x52]1802cf8c909804d.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802dc4a52838fe.png[/img] B: [img=171x51]1802dc4a5af1a11.png[/img] C: [img=186x51]1802dc4a6840d96.png[/img] D: [img=188x52]1802dc4a716cf73.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802dc3d74aaa84.png[/img] B: [img=171x51]1802dc3d8194fc8.png[/img] C: [img=186x51]1802dc3d8e36561.png[/img] D: [img=188x52]1802dc3d96b0843.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802dc249480238.png[/img] B: [img=171x51]1802dc24a10f3cd.png[/img] C: [img=186x51]1802dc24ad7109f.png[/img] D: [img=188x52]1802dc24b486030.png[/img]

下列不等式中正确的是（ ）． A: [img=171x51]1802cf90c9bd8aa.png[/img] B: [img=171x51]1802cf90d6322e3.png[/img] C: [img=186x51]1802cf90dde4881.png[/img] D: [img=188x52]1802cf90e692dd7.png[/img]

用边界值分析法，假定50 A: X=50，X=80 B: X=50，X=49，X=80，X=81 C: X=51，X=81 D: X=50，X=81