Prove whether the following inferences are valid using the long or short truth table method. If they are invalid, give the counterexample. A > -B |= B > -A​

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

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.

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28