11. 解：································································································ 2分

···························································································································· 5分

检验：将代入原方程，左边右边································································· 7分

所以是原方程的根································································································ 8分

(将代入最简公分母检验同样给分)

10. 解 (Ⅰ)

	速度(千米／时)	所用时间(时)	所走的路程(千米)
骑自行车			10
乘汽车			10

　　　　　　　　　　　　　　　　　　　 ···························································· 3分

(Ⅱ)根据题意，列方程得．　 ································································· 5分

解这个方程，得．　　 ······················································································· 7分

经检验，是原方程的根．

所以，．　　　　　　　　　

答：骑车同学的速度为每小时15千米． ······································································ 8分

9. 解法一：原式····························································· 2分

······················································································································· 6分

当时，原式···················································································· 8分

解法二：原式··········································· 2分

······················································································································· 6分

当时，原式···················································································· 8分

8. 解法一：设乙班有人捐款，则甲班有人捐款．············································ 1分

根据题意得：

········································································································· 5分

解这个方程得．································································································· 8分

经检验是所列方程的根．··················································································· 9分

(人)

答：甲班有48人捐款，乙班有45人捐款．································································· 10分

解法二：设甲班有人捐款，则乙班有人捐款．················································· 1分

根据题意得：

········································································································· 5分

解这个方程得．································································································· 8分

经检验是所列方程的根．··················································································· 9分

(人)

答：甲班有48人捐款，乙班有45人捐款．································································· 10分

7. 设原计划平均每天改造道路x千米，,根据题意，得…………1分

………………………………………………………4分

解这个方程，得x＝0.2………………………………………………6分

经检验，x＝0.2是原方程的解.

答:原计划平均每天改造道路0.2千米.…………………………7分四、认真思考，你一定能成

6. 解：　 　………………………………………2分

＝　　　　 …………………………………………………………3分

＝　　　　 …………………………………………………………4分

＝．　　　　 ……………………………………………………………………5分

当时，原式＝．　 ……………………………………7分

5. 原式······················································································ 2分

························································································· 4分

4. 　………………………………………………………………………1分

　 ……………………………………………………………………………2分

经检验：是原方程的解　 …………………………………………………1分

3. 解：原式=

2. 解：原式＝　　 ……………………………2分

＝　　　　 …………………………………………3分

＝．　　　 …………………………………………………………4分

当，时，

原式＝．　 …………………………………………………6分