Going to the right or left when doing translation effects the x coordinate. In this case, the x coordinate is 14. Since we are moving 6 units to the left, we must subtract 6 from 14. Moving to the left is negative and moving to the right is positive.
Domain values are the possible x values that can be entered into the function, or the inputs. Range values are the y values, or the outputs. By inserting every value in the set into the function, we get the outputs (y values)