What are three different patterns of a number triangle ?

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Which of these triangle pairs can be mapped to each other using two reflections?