Simplifying algebraic expressions -8(2k-7)

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

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?