№ 84
1) (3 2/3 + 1 3/4) : (6 7/12 - 2 1/4) * 0,8 = 1
1) 3 2/3 + 1 3/4 = 3 8/12 + 1 9/12 = 4 17/12 = 5 5/12
2) 6 7/12 - 2 1/4 = 6 7/12 - 2 3/12 = 4 4/12 = 4 1/3
3) 5 5/12 : 4 1/3 = 65/12 : 13/3 = 65/12 * 3/13 = 5/4
4) 5/4 * 0,8 = 5/4 * 8/10 = 5/4 * 4/5 = 1
2) (4 2/5 : 1 3/5 + 2 4/7 - 8 1/2 : 14) : (2 3/8 - 1 11/14) = 8
1) 4 2/5 : 1 3/5 = 22/5 : 8/5 = 22/5 * 5/8 = 22/8 = 2 6/8 = 2 3/4
2) 8 1/2 : 14 = 17/2 * 1/14 = 17/28
3) 2 3/4 + 2 4/7 = 4 37/28 = 5 9/28
4) 5 9/28 - 17/28 = 4 37/28 - 17/28 = 4 20/28 = 4 5/7
5) 2 3/8 - 1 11/14 = 2 21/56 - 1 44/56 = 1 77/56 - 1 44/56 = 33/56
6) 4 5/7 : 33/56 = 33/7 * 56/33 = 56/7 = 8