(1 целых 8/13 * 13/42 + 5 целых 5/7 : 8/21) : (8 целых 1/8 + 3 целых 1/2) = ?

1) 21/13 * 13/42 = 1/2
2) 40/7 : 8/21 = 15
3) 1/2+15 = 15,5
4) 65/8 +7/2 = 11,625
5) 15,5 : 11,625 = 4/3
ответ: 4/3

(1 8/13 • 13/42 + 5 5/7 : 8/21) : (8 1/8 + 3 1/2) =
= ( 21/13 • 13/42 + 40/7 : 8/21) : (65/8 + 7/2) =
= (1/2 + 15) : (65/8 + 28/8) =
= (1/2 + 30/2) : 93/8 = 31/2 : 93/8 = (31•8)/(2•93) =
= 4/3 = 1 1/3