Odpowiedź:
Zadanie 2.
18 minut to 18/60 godziny = 9/30 godziny
45 minut to 45/60 godziny = 3/4 godziny
75 minut to 75/60 godziny = 15/12 = 1 i 3/12 = 1 i 1/4
Zadanie 3.
a) 8 i 4/11 - 5 i 9/11 = 7 i 15/11 - 5 i 9/11 = 2 i 6/11
b) 8 i 5/6 + 5 i 3/8 = 8 20/24 + 5 i 9/24 = 13 i 29/24 = 14 i 5/24
c) 7 i 2/3 - 4 i 2/5 = 7 i 10/15 - 4 i 6/15 = 3 i 4/15
d) 1 i 2/7 * 4 i 1/12 = 9/7 * 49/ 12 = 63/12 = 5 i 2/12 = 5 i 1/6
e) 4 i 8/15 : 3 i 2/5 = 68/15 : 17/5 = 68/15 : 5/17 = 20/1 = 20
:)
