Carmen received an $80 gift card for a coffee store. she used it in buying some coffee that cost $7.74 per pound. after buying the coffee, she had $33.56 left on her card. how many pounds of coffee did she buy?

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.