Math problem. I not smort

What is (28 + 7 + 6 + 3) x 1/2 show your work

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.