Question

► Problemas Propostos
1) Resolva as operações indicadas:

a-) 3/8 + 5/6 =

b-)5/6 - 3/10 =

c-)20/42 . 56/45 =

d-)21/32 : 49/72 =​

Answer 1

Resposta:

Explicação passo-a-passo:

a) 3/8 + 5/6 =

mmc(8,6)

8, 6 | 2

4, 3 | 2

2, 3 | 2

1, 3 | 3

1, 1 | 1

mmc(8,6) = 2 . 2 . 2 . 3 = 24

3/8+5/6=(9+20)/24=29/24

b) 5/6 - 3/10 =

mmc(6,10)

6, 10 | 2

3, 5 | 3

1, 5 | 5

1, 1 | 1

mmc(6,10) = 2 . 3 . 5 = 30

5/6-3/10 =(25-9)/30=16÷2/30÷2=8/15

c)

20/42 . 56/45=(20.56)/(42.45)=1120/1890=1120÷70/1890÷70=16/27

d)

21/32 : 49/72=21/32.72/49=(21.72)/(32.49)=1512/1568=1512÷56/1568÷56=27/28