Question

como calcular as expressões:
a) 7/6 . 3/5 - 1/8 : 5/6 =
b) 3/4 + 9/5 : 1/6=
c) 1/2 - 1/5 : 2 =

Answer 1

a)

= 7/6 . 3/5 - 1/8 : 5/6

= 21/30 - 1/8 . 6/5

= 21/30 (:3)/(:3) - 6/40 (:2)/(:2)

= 7/10 - 3/20

MMC (10,20) = 20

= (2.7 - 1.3)/20

= (14 - 3)/20

= 11/20

b)

= 3/4 + 9/5 : 1/6

= 3/4 + 9/5 . 6/1

= 3/4 + 54/5

= (5.3 - 4.54)/20

= (15 - 216)/20

= - 201/20

MMC (4,5) = 20

4,5: 2

2,5: 2

1,5: 5

1,1 = 2.2.5 = 20

c)

= 1/2 - 1/5 : 2

= 1/2 - 1/5 . 1/2

= 1/2 - 1/10

= (5.1 - 1.1)/10

= (5 - 1)/10

= 4/10 (:2)/(:2)

= 2/5