4x-5 13y+6 18:z-17 12, x=59, y=316, z=720

4×5/9 - 5 1/3×3/16 + 6 1/8÷7/20 = 20/9 - 16/3×3/16 + 49/8×20/7 = 20/9 - 1 + 35/2 = 2 1/9 - 1 + 17 1/2 = (2-1+17) + (1/9 +1/2) = 18 + (2+9)/18 = 18 11/18