Perform the indicated calculations graphically for the following three mixtures. Use a triangular diagram with xa on the horizontal axis and xc on the vertical axis.

Q: 2000 lb: xa = 0.7, xb = 0.2, xc = 0.1.

R: 1000 lb: xa = 0.3, xb = 0.5, xc = 0.2.

S: 3000 lb: xa = 0.1, xb = 0.2, xc = 0.7.

a.) Add A, B and C.

b.) Add A to C, then subtract B.

c.) Subtract B from C, then add A.

d.) Subtract R from Q, then add S.