Algebra: Chapter 9, Lesson 1, page 400.
Sets, Intersections and Unions
A set is a well-defined collection of objects called members or elements.
- Roster notation LISTS the members of the set.
- Set-Builder Notation gives a DESCRIPTION of how the set is built.
The intersection of 2 sets `A` and `B`, written `A ∩ B` is the set of all members that are COMMON to both sets. We say ” A intersection B”.
The union of 2 sets `A` and `B`, written `A ∪ B` is the set of all members that are in `A` or `B` or in both. If an intersection is EMPTY, we say the intersection is the empty set which is symbolized as `∅`.
All of these concepts are described here too with examples!
Two of tonight’s homework problems solved by MrE are here! Just click it!
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Algebra 1a: Chapter 3, Lesson 10, page 152.
Using Percent
The ratio of numbers to 100 is called percent. Percent means “per one hundred”. We use whickity-whack divide, the method that Ms. Phillips taught us in 7th grade. Here is my podcast that describes the process!
Two of tonight’s homework problems solved by MrE are here! Just click it!