问题 解答题

(1)(分解因式)-3a3b+18a2b2-27ab3

(2)3x(x+1)≤(x+2)(3x-1)

答案

(1)原式=-3ab(a2-6ab+9b2

=-3ab(a-3b)2

(2)3x(x+1)≤(x+2)(3x-1),

去括号得:3x2+3x≤3x2-x+6x-2,

移项得:3x2+3x-3x2+x-6x≤-2,

合并同类项得:-2x≤-2,

把x的系数化为1得:x≥1.

写作题

请仔细审图,假设这是Jane的房间,请你根据提示词汇帮她描述一下房间内物品的摆放情况。

要求:以第一人称描述,不少于60词。开头已给出,不计入总词数。

提示词汇:bed, picture, wall(墙), bookcase, dresser, alarm clock, computer, CDs

This is my room. It’s very clean!

                                                                  

                                                                 

                                                                  

                                                                 

                                                                  

                                                                 

                                                                  

                                                                 

                                                                 

                                                                 

单项选择题