Resposta:
1) a) 60
b) 60
c) 90
d) 70
e) 105
f) 42
g) 24
h) 90
2) a) 1
b) 1
c) 9/10
d) 3/8
e) 3/2
f) 10/13
g) 5/7
h) 10/3
3) a) 5/6
b) 12/35
c) 13/40
d) 8/15
e) 5/12
f) 14/45
Explicação passo-a-passo:
1-)
A) MMC de 20 e 30
20, 30 | 5
ㅤ 4, 6 | 2ㅤㅤㅤ5 . 2 . 2 . 3 = 60
ㅤ 2, 3 | 2
ㅤ 1, 3 | 3
ㅤ 1, 1
B) MMC de 15 e 20
15, 20 | 5
ㅤ3, 4 | 3ㅤㅤㅤ5 . 3 . 2 . 2 = 60
ㅤ1, 4 | 2
ㅤ1, 2 | 2
ㅤ 1, 1
C) MMC de 6 e 45
6, 45 | 3
2, 15 | 5ㅤㅤㅤ3 . 5 . 2 . 3 = 90
2, 3 | 2
1, 3 | 3
1, 1
D) MMC de 14 e 5
14, 5 | 5
14, 1 | 7ㅤㅤㅤ5 . 7 . 2 = 70
2, 1 | 2
1, 1
E) MMC de 7, 3 e 15
7, 3, 15 | 3
7, 1, 5 | 5ㅤㅤㅤ3 . 5 . 7 = 105
7, 1, 1 | 7
ㅤ1, 1, 1
F) MMC de 2, 3 e 7
2, 3, 7 | 2
1, 3, 7 | 3ㅤㅤㅤ2 . 3 . 7 = 42
1, 1, 7 | 7
1, 1, 1
G) MMC de 6, 8 e 12
6, 8, 12 | 2
3, 4, 6 | 3ㅤㅤㅤ2 . 3 . 2 . 2 = 24
1, 4, 2 | 2
1, 2, 1 | 2
1, 1, 1
H) MMC de 9, 15 e 10
9, 15, 10 | 3
3, 5, 10 | 3ㅤㅤㅤ3 . 3 . 5 . 2 = 90
1, 5, 10 | 5
1, 1, 2 | 2
ㅤ1, 1, 1
2-
a) 1/3 + 2/3 = 3/3 = 1
b) 2/7 + 5/7 = 7/7 = 1
c) 8/10 + 1/10 = 9/10
d) 4/8 - 1/8 = 3/8
e) 1/4 + 5/4 = 6/4 = 3/2
f) 7/13 + 3/13 = 10/13
g) 4/7 + 1/7 = 5/7
h) 8/3 + 2/3 = 10/3
3-)
a) 1/3 + 1/2 = 2/6 + 3/6 = 5/6
b) 1/7 + 1/5 = 5/35 + 7/35 = 12/35
c) 1/8 + 1/5 = 5/40 + 8/40 = 13/40
d) 1/3 + 1/5 = 5/15 + 3/15 = 8/15
e) 1/4 + 1/6 = 6/24 + 4/24 = 10/24 = 5/12
f) 1/9 + 1/5 = 5/45 + 9/45 = 14/45
