1) x/3 = 20/y =4 2) 9/-x = y/5 = -3 3) x/2 = -y/3 = z/-4 = -18/9 4) 15/x = y/4 = z/16 = 6/-8 5) -4/x = 3/y = -1/2 6) -6/12 = x/8 = -7/y = z/-18