题干

将方程x2-6x+3=0左边配成完全平方式,得到的方程是(     )

A:(x-3)2=-3

B:(x-3)2=6

C:(x-3)2=3

D:(x-3)2=12

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答案(点此获取答案解析)

B

同类题1

阅读理解

    The bike-sharing companies that are powering a transportation revolution in China's urban centers are not like those in the rest of the world. Their bikes have no docking ports or assigned zones for parking. Instead, riders open their smartphone apps, hop on, and start riding. So easy!

    In 2015, Ofo, China's bike-share pioneer, launched its first fleet of bicycles in Beijing. The bikes' bright yellow frames were soon met by the orange-rimmed(镶边), basket-equipped models launched by Mobike, Ofo's main competitor today. In little over a year, the two companies have had a huge impact on revitalizing (重振) cycling in China, particularly among young people.

    Ofo placed 1 million bicycles across 35 cities and registered 15 million users in its first years, while Mobike has now gained more than 10 million unique users and bicycles in 21 cities. Inspired by their success, at least 10 other companies have jumped into the market, launching their own app-powered, brightly colored bikes in quick succession. But Mobike and Ofo are far ahead of them.

    The two industry leaders each take a different marketing method to a similar product. The Mobike app uses GPS to display bikes' locations to users. They can use the map to reserve a bike and walk over to it. A scan of the bike's QR code (二维码) unlocks the bike, and when users manually(手动地) lock the bike at the end of their trip, the app records the trip's end and the bike will pop back up on the map as available. Equipped with this wireless technology, Mobikes cost between 1,000 and 3,000 yuan. Rides cost 1 yuan for an hour or a half hour, depending on whether a user chooses a “Lite” or regular bike, and the deposit (押金) required to the service is 299 yuan.

    Ofo, meanwhile, is devoted not just to producing its own bikes, which have slim yellow bodies and cost about 250 yuan, but also to connecting existing bikes to its network----- a philosophy that begins with the practice of 2000 bikes offered to a campus bike-share program. The 2000 bikes were the first generation of Ofo. Yet the majority of the company's bikes are currently ones that have been specially manufactured and fitted with their lock system. Unlike Mobike,Ofo bikes themselves are offline: their locations are tracked through users' cell phones. Users find a free bike, enter the license plate number into their app, and receive the bike unlock code. When they have reached their destination, they end the ride on the app and manually lock the bike. Rides cost 1 yuan for an hour and the deposit is 99 yuan.

同类题4

阅读材料,完成下列要求。

材料一:中国古代绅士一般从贡生和举人及其以上功名、学品、学衔当中选拔,但这些人也未必都能得到任命;还有通过捐纳获得了虚职而实际没有任用的;曾经做过官,有的离休退职或罢官的等等。整个绅士阶层可分为上下层。上层绅士由学衔或官衔较高的绅士组成,而下层绅士主要包括学衔较低或通过捐纳获得较低功名的绅士。绅士在中国古代社会中是居于领导地位的社会集团,绅士通常被看做能与地方官员平起平坐。他们的特权主要体现在礼仪、法律、经济三个方面。

——摘编自张仲礼《中国绅士研究》

材料二:近代绅士集团的转型,最初表现为绅与商的交叉渗透。绅商的互渗现象又经历了一个商对绅的渗透,绅向商的转化的变动过程。在这一变动过程中,社会价值定向由传统的绅士集团转向了近代的商人阶层。甲午战争以后,伴随着近代中国社会的剧烈变动,“逆向渗透”迅速地被“顺向渗透”所取代。绅士阶层在“救亡图存”的民族精神感召下和“商战”思潮的导引下,相率“弃士经商”。传统的“功名”身份已失去了原有的强大吸引力,绅士们热心于经营商务,寻找新的出路。一时秀才工厂、生员公司林林而立。“绅士”以其特有的社会地位投资于近代企业,借助于“通官商之邮”的特殊地位,很快成为“既贵且富”的重要社会势力。

——摘编自王先明《近代中国绅士集团转型初探》