Is y=6x a liner equation

Use set builder notation to represent the following set: { -3, -2, -1, 0}

Joseph haydn pet store offers wide variety of leashes for dogs. the store purchases one popular type of leash from its manufacturer for $4.38 each. joseph haydn pets marks up leashes at a rate of 238% of cost. what is the retail price of the popular leash?

What is the least common factor of 6 and 8