题目

已知-1＜a+b＜3且2＜a-b＜4,求2a+3b的取值范围. 答案：-＜2a+3b＜ 解析: 设2a+3b=m(a+b)+n(a-b), ∴,                                                         4分 ∴m=,n=-.                                                        6分 ∴2a+3b=(a+b)-(a-b).                                           �- Sorry to have hurt you.   - __________. You didn’t mean to, did you?   [     ]A. Forget it     B. Take it easyC. All rightD. Don’t say so