Shade 50% of this figure, worth 16 points

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

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.