Select all of the following that are quadratic equations.. x2 - 2x = 4x + 1. x3 - 6x2 + 8 = 0. 5x - 3 = 0. 2x2+ 12x = 0. 5x - 1 = 3x + 8. 9x2 + 6x - 3 = 0

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.