Б)
1)7 1/2 - 4,25 = 7,5 - 4,25 = 3,25
2)3,25 : 9/20 = 3 1/4 : 9/20 = 13/4 * 20/9 = 65/9 = 7 2/9
3) 3 3/8 - 7 2/9 = 3 27/72 - 7 16/72 = -3 61/72
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г)
1) -3 3/5 : 2,7 = -18/5 * 10/27 = -4/3
2) 2,7 : 3 3/5=27/10 * 5/18 = 3/4
3) -4/3 + 3/4 = -16/12 + 9/12 = -7/12