Pls help what’s 8 divided by 531 im not good at long division

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.

Me. i can't figure out this question. give an explanation too. .

Find the amplitude of a sinusoidal function that models this temperature variation