Question

設60≤a≤84,28≤b≤33,求a+b,a-b及的取值范圍.

Answer 1

解析:因為60≤a≤84,                                         ①

28≤b≤33,                                                      ②?

由①+②,得88≤a+b≤117,-33≤-b≤-28.            ③?

由①+③,得27≤a-b≤56,              ④

由①×④,得