Help Pleasee ! I don’t understand this

Aparallelogram has two side lengths of 5 units. three of its sides have equations y = 0, y = 2, y = 2x. find the equation of the fourth side.

Carrie started with 12 ounces of water when she begin to walk. when she was finish walking she had 2 1/4 ounces of water left. how much did she drank

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.