( 8 - 6 1/4) : (-5/8) - 9 * (-1/2 - 2/5) = 5,3
1) 8 - 6 1/4 = 8 4/4 - 6 1/4 = 1 3/4
2) - 1/2 - 2/5 = - 5/10 - 4/10 = - 9/10
3) 1 3/4 : (-5/8) = - (7/4 : 5/8) = - (7/4 * 8/5) = - 14/5 = - 2 4/5
4) 9 * (- 9/10) = - (9 * 9/10) = - 8 1/10
- 2 4/5 - (-8 1/10) = - 2 4/5 + 8 1/10 = - 14/5 + 81/10 = -28/10 + 81/10 = 53/10 = 5 3/10 = 5,3
2 сут+4 сут=6 суток, 15ч+14ч=29ч,= 29-24=5ч,ответ:7 суток 5 часов
8х+42,15=44,75
8х=44,75-42,15
8х=2,6
х=2,6÷8
х=0,325