CР二、填空题(每小题3分,本小题共18分)Р11.2.5×10-6 12.1<狓<6 13.±10 14.3 15.65° 16.15Р三、解答题(本大题共5小题,共72分)Р17.解:(1)狓3狔-4狓2狔+4狓狔Р =狓狔(狓2-4狓+4)!!!!!!!!!!!!!!!!!!!!!!! 3分Р =狓狔(狓-2)2 !!!!!!!!!!!!!!!!!!!!!!!!! 6分Р (2)(犿+2狀-3)(犿-2狀+3)Р =[犿+(2狀-3)][犿-(2狀-3)] !!!!!!!!!!!!!!!!! 2分Р =犿2-(2狀-3)2 !!!!!!!!!!!!!!!!!!!!!!! 4分Р =犿2-(4狀2-12狀+9) !!!!!!!!!!!!!!!!!!!!! 5分Р =犿2-4狀2+12狀-9 !!!!!!!!!!!!!!!!!!!!!! 6分Р (3)解:去分母,得2(1-狓)=狓-2(狓-2), !!!!!!!!!!!!!! 3分Р 去括号,得2-2狓=狓-2狓+4,Р 移项,得-2狓-狓+2狓=4-2,Р 合并同类项,得-狓=2 ,Р 系数化为1,得狓=-2 , !!!!!!!!!!!!!!!!!! 6分Р 检验:当狓=-2时,2(狓-2)≠0,Р ∴狓=-2是原分式方程的解. !!!!!!!!!!!!!!!! 7分Р 狓2+4 狓+2Р (4)原式= · !!!!!!!!!!!!!!!!! 3分Р 2(狓+2)(狓-2) 狓2+4Р 1Р = , !!!!!!!!!!!!!!!!!!!!!!! 5分Р 2(狓-2)Р 将狓=1010代入,得:Р 1 1Р 原式= = . !!!!!!!!!!!!!!!!!! 7分Р 2×(1010-2) 2016Р18.解:(1)所作图形如图所示:Р !!!!!!!!!!!!!!!! 4分Р 八年级数学试题参考答案第1页(共2页)
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