which expression is equivalent to sin(pi/12)cos(7pi/12)-cos(pi/12)sin (7pi/12)? a) cos(-pi/2) b) sin(-pi/2) c) cos(2pi/3) d) sin(2pi/3)

Mike wants to make meatloaf. his recipe uses a total of 8 pounds of meat. if he uses a 3 to 1 ratio of beef to pork, how much pork will he use? enter your answer as a mixed number in simplest terms.