6.
1) 6/10 + 17/40 = 24/40 + 17/40 = 41/40
2) 20 5/9 + 4 4/9 = 24 9/9 = 25
3) 41/40 : 25 = 41/40 * 1/25 = 41/1000 = 0,041
Ответ: В) 0,041
7. x + 2,2 = 8 1/12 - 3 2/3 = 7 13/12 - 3 8/12 = 4 5/12
x = 4 5/12 - 2 1/5 = 4 25/60 - 2 12/60 = 2 13/60
Ответ: D) 2 13/60
8.
x = 1 : 2/3 = 3/2
8/3 * 3/2 + 4 10/12 - 5 7/12 = 4 + 4 10/12 - 4 19/12 = 4 - 9/12 = 3 3/12 = 3 1/4
Ответ: A) 3 1/4