Someone please help me answer this, I am so confused.

What is the volume of this square pyramid?

What value of x is in the solution set of 4x - 12 s 16 + 8x? -10 -9 -8 -7

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.