If light passes in an angle to a surface with a particular refractive index it refracts. This change in direction is due to a change in velocity. As light , for example, travels from air through water, it slows down, allowing it to continue travelling at a different angle or direction.
Answer: A 65 Explanation: using PEMDAS you substitute 4 in for k and add 9+4 because it’s in parenthesis. Then you multiply the 13 you get from that by 5 and get 65.
