Given the equation 5 + x - 12 = x - 7. part a. solve the equation 5 + x - 12 = x - 7. in your final answer, be sure to state the solution and include all of your work part b. use the values x= 4, 0,5 to prove your solution to the equation 5 + x - 12 = x - 7. in your final answer, include all of your calculations.