If a + b = -1a+b=−1a, plus, b, equals, minus, 1 and x + y + z = 2x+y+z=2x, plus, y, plus, z, equals, 2, what is 7a + 7b + 6z + 6x + 6y7a+7b+6z+6x+6y7, a, plus, 7, b, plus, 6, z, plus, 6, x, plus, 6, y?

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.