*60000
8000
_______
480000
____________
480000000
При а = -3, -4, -5
-8 <= -3
-8 <= -4
-8 <= -5
-3 >= -3
-3 >= -4
-3 >= -5
30/6=5 руб - цена 1 карандаша
42/5=8 карандашей и 2 рубля останется
1)
3 1/15 + 2 7/25 = (3 + 2) + (1/15 + 7/25) =
= 5 + (5/75 + 21/75) = 5 + 26/75 = 5 26/75,
2)
2 7/10 + 9 2/15 = (2 + 9) + (7/10 + 9/15) = 11 + (21/30 + 18/30) = 11 + 39/30 = 11 + 1 9/30 = 12 9/30 = 12 3/10,
1)
12 5/9 - 7 1/6 = (12 - 7) + (5/9 - 1/6) = 5 + (10/18 - 3/18) = 5 + 7/18 = 5 7/18,
2)
7 1/4 - 3 7/15 = (7 - 3) + (1/4 - 7/15) =
= 4 + (15/60 - 28/60) = 4 - 13/60 = 3 47/60
27:9=3 м на 1 платье
60:3=20 платьев можно сшить