Verified answer

1.

3)

13 7/9 - (2,64 + 2 7/9) = 13 7/9 - 2,64 - 2 7/9 =

= (13 7/9 - 2 7/9) - 2,64 = 11 - 2,64 = 8,36,

2.

3)

(0,3 - 1/20) : (3/4 - 1,25) = -1/2  (или -0,5),

1)) 0,3 - 1/20 = 3/10 - 1/20 = 6/20 - 1/20 = 5/20 = 1/4,

2)) 3/4 - 1,25 = 3/4 - 1 1/4 = 3/4 - 5/4 = -2/4 = -1/2,

3)) 1/4 : (-1/2) = -1/4 * 2/1 = -2/4 = -1/2  (или -0,5),

4)

(2,7 - 1/5) : (1/2 + 4,5) = 1/2  (или 0,5),

1)) 2,7 - 1/5 = 27/10 - 2/10 = 25/10 = 2 1/2  (или 2,5),

2)) 1/2 + 4,5 = 5/10 + 45/10 = 50/10 = 5,

3)) 2,5 : 5 = 1/2  (или 0,5)