On a graph would the x-axis be sideways or straight up and would the y-axis be straight up or sideways

Solve the system of equations. y= 2x y= x^2 - 15

Reflect the point (7,0) across the y-axis

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.