construct an algebraic expression containing at least three different mathematical operations (+, -,÷, x) but consisting of one term only​

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

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.

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?