2/9 *(6.9c - 1 1/2 d) - 4.8*(5/8 c - 2.5d) = 2/9 * (69/10c - 3/2d) - 48/10 * (5/8c - 5/2d) = 2/9 * (69/10c - 3/2d) - 24/5 * (5/8c - 5/2d) = 2/9 * 69/10 c - 2/9 * 3/2d - 24/5 * 5/8c + 24/5 * 5/2d = 31/5c - 1/3d - 3c + 12d = 31/5c - 15/5c - 1/3d + 36/3d = 16/5c + 35/3d