Question

Calcule:
10/5 : 7/3 =
2- Calcule o valor das expressões:
a)(2/5 + 3/2) + (5/4 + 2/5) =
b)(7/8 - 5/6) + (8/9 - 7/9) =
Me ajudem!

Answer 1

10/5   :   7/3  =   10/5  x  3/7  =   30/35 simplifica por 5 = 6/7

2)
a) (2/5  + 3/2 )  + (5/4  +  2/5 ) = 
m.m.c = 10
(4/10 + 15/10)  +  m.m.c = 20
(4/10 + 15/10) + (25/20  + 8/20) = 
(19/10)  +  (33/20) = 
m.m.c = 20
38/20  + 33/20 = 71/20

b)(7/8  -  5/6 )  +  (8/9  - 7/9) = 
m.m.c = 24
(21/8  -  20/24)  +  (  1/9)  = 
(1/24)   +  (1/9) = 
m.m.c = 72
3/72  + 8/72 = 11/72