问题
解答题
解方程：
（1）3y2-5y=0
（2）x2-4x-7=0
答案
（1）3y2-5y=0
y（3y-5）=0．
解得y1=0，y2=
．5 3
（2）由x2-4x-7=0，得
∵a=1，b=-4，c=-7
∴x=
=-b± b2-4ac 2a
=2±4± 16+28 2
．11
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解方程：
（1）3y2-5y=0
（2）x2-4x-7=0
（1）3y2-5y=0
y（3y-5）=0．
解得y1=0，y2=
．5 3
（2）由x2-4x-7=0，得
∵a=1，b=-4，c=-7
∴x=
=-b± b2-4ac 2a
=2±4± 16+28 2
．11
Are you nervous when you stand in front of the public? Are you afraid to make a speech? Li Jun, a middle school boy, felt shy when he was making a speech the other day. Li had thought it would be quite easy to speak in front of 1 classmates. "I was wrong. It was very different and much 2 than talking to my classmates during playtime," Li said. "I tried, but it was really difficult to speak. I felt like a mute (哑巴) and wanted to leave the classroom 3 " Li is not alone. Many middle school students now have the same 4 : they can talk about their ideas freely 5 their best friends after class, but can't speak in public. According to Zhou Hong, a teacher from a university, the main reason is that schools in China pay more attention to writing instead of 6 . Zhou hopes schools can give students more chances to open their 7 , such as speech competitions, English corners and class discussions. Students can join in any one they want to. 8 he also gives some advice to students. "During your free time you should 9 more. When you're speaking in public, take it easy. Just imagine you're talking to nobody and speak up your ideas clearly," Zhou said. "That 10 a fine public speech and you'll feel confident. "
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