3926 use each digit once, make the largest 4-digit number​

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.

What is the length of an with endpoints a 3,2 and b 8,14

Write two subtraction equations that are equivalent to 5 + 12 = 17.