Answer:
a) 3
b) 4
c) 5
d) 1
e) 2
Step-by-step explanation:
Remember the key concepts for each part:
a) Compound inequalities are statements like a<x<b, which are equivalent to a<x and x<b (in this case, two inequalities). They can be formed by more inequalities, for example, 1<2<3<...<20 is a compound inequality formed of 19 inequalities (1<2, 2<3,.., 19<20).
b) Elements are related to sets by the membership relation, denoted by "∈". If A is a set, the statement "x∈A" means "x is a member of A" or "x is an element of A."
c) Sets are described as a collection of objects. These objects are said to belong to the set, that is, they are the elements of the set as in b).
d) If A and B are sets, the union of A and B, denoted by A∪B is the set whose elements are elements of A or elements of B. More formally, A∪B={x:x∈A is true or x∈B is true}. The word "or" used here is not exclusive: if x∈A and x∈B then x∈A∪B.
e) If A and B are sets, the intersection of A and B, denoted by A∩B is the set whose elements belong to A and belong to B. More formally, A∩B={x:x∈A is true and x∈B is true}.