If f(x) = 3x^5+ 4, then what is the remainder when f(x) is divided by x – 2?

Pls! does anybody know a shortcut for answering these types of questions in the future?

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?

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)