Plz help me answer i need help​

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

Plzzz i beg u so much asaaaap ! what is the slope of this line? enter your answer in the box.

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle