Question

b) 2/8+1/10=

d) 9/4+5/6=

F)9/4-5/6=

g) 1/7+2/3+2/8=

h) 1/7+2/3-2/8=

I) 2/3-1/7+2/8=

j)9/40+2/30-1/20=
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Answer 1

b) 2/8+1/10

mmc

8 , 10 2

4 , 5 2

2 , 5 2

1 , 5 5

1 , 1 / 2 . 2 . 2 . 5 = 40

5.2/40 + 4.1/40

10/40 + 4/40 = 14/40

Simplificação:

14/40 = 7/20

d) 9/4+5/6

mmc

4 , 6 2

2 , 3 2

1 , 3 3

1 , 1 / 2 . 2 . 3 = 12

3.9/12 + 2.5/12

27/12 + 10/12 = 37/12

F)9/4-5/6

27/12 - 10/12 = 17/12

g) 1/7+2/3+2/8

mmc

7 , 3 , 8 2

7 , 3 , 4 2

7 , 3 , 2 2

7 , 3 , 1 3

7 , 1 , 1 7

1 , 1 , 1 / 2 . 2 . 2 . 3 . 7 = 168

24.1/168 + 56.2/168 + 21.2/168

24/168 + 112/168 + 42/168

136/168 + 42/168 = 178/168

Simplificação:

178/168 = 89/84

h) 1/7+2/3-2/8

24/168 + 112/168 - 42/168

136/168 - 42/168 = 94/168

Simplificação:

94/168 = 47/84

I) 2/3-1/7+2/8

112/168 - 24/168 + 42/168

88/168 + 42/168 = 130/168

Simplificação:

130/168 = 65/84

j)9/40+2/30-1/20

mmc

40 , 30 , 20 2

20 , 15 , 10 2

10 , 15 , 5 2

5 , 15 , 5 3

5 , 5 , 5 5

1 , 1 , 1 / 2 . 2 . 2 . 3 . 5 = 120

3.9/120 + 4.2/120 - 6.1/120

27/120 + 8/120 - 6/120

35/120 - 6/120 = 29/120