5 1/6:31+(3 1/4+2 1/6):2 3/5-2/3:4/9

5 1/6 : 31 + (3 1/4 + 2 1/6)  : 2 3/5 - 2/3 : 4/9 =
= 5 1/6 : 31 + (65/12) : 2 3/5 - 2/3 : 4/9 =
= 1/6 + (65/12) : 2 3/5 - 2/3 : 4/9 = 1/6 + 25/12 - 2/3 : 4/9 =
= 1/6 + 25/12 - 3/2 = 3/4 =