Odpowiedź:
a)
2/3 + 1/5 = 10/15 + 3/15 = 13/15
b)
2 i 1/2 - 3/4 = 2 i 2/4 - 3/4 = 1 i 6/4 - 3/4 = 1 i 3/4
c)
12 i 1/4 - 8 i 1/2 = 11 i 5/4 - 8 i 2/4 = 3 i 3/4
d)
(3/4 + 2/3) * 6= (9/12 + 8/12)*6 = 17/12 * 6 = 17/2 * 1= 17/2 = 8 i 1/2
e)
3/4 * 60 = 3/1 * 15 = 45/1 = 45
f)
7/15 * 10/21 = 1/3 * 2/3= 2/9
g)
3 i 3/4 * 4 i 1/5 = 15/4 * 21/5 = 3/4 * 21/1 = 63/4 = 15 i 3/4
h)
4/5 : 2= 4/5 * 1/2 = 2/5 * 1/1 = 2/5
i)
2 i 1/4 : 6 = 9/4 * 1/6 = 3/4 * 1/2 = 3/8
j)
2/3 : 5/6 = 2/3 * 6/5 = 2/1 * 2/5 = 4/5
k)
1 i 1/2 : 2/9 = 3/2 * 9/2= 27/4 = 6 i 3/4
l)
4 * 3 i 1/8 - (2 i 1/2)²=
= 4 * 25/8 - (5/2)²=
= 1 * 25/2 - 25/4 =
= 50/4 - 25/4 =
= 25/4 =
=6 i 1/4
m)
(5 i 1/2 - 3 i 1/4)² : 7 =
= (5 i 2/4 - 3 i 1/4)² : 7 =
= (2 i 1/4)² : 7 =
= (9/4)² * 1/7 =
= 81/16 * 1/7 =
= 81/112
Szczegółowe wyjaśnienie:
