Question

calcule as expressoes :

a)$\frac{2}{5}+( -\frac{2}{7}):( \frac{5}{14})=$
b)$[(- \frac{1}{5}):(- \frac{1}{7})-(- \frac{2}{11}):( \frac{4}5} )]=$

Answer 1

olá!

a)   2

  ---------   +   ( -2/7) : ( 5/14) =

      5

    2             2             14

--------- -  --------- x  ---------

   5              7              5

   2                   2     

--------- - 2 x    -------

   5                  5

   2           2 x 2  

-------- -  ---------

   5             5

 

   2 - ( 2 x 2 )

  ------------------

          5

 

    2 - 4              -2  

------------- =   -----------  

      5                   5

b) [ ( - 1/5 ) :( -1/7) - ( -2/11) : ( 4/5) ]

 

  [  - 1/5 * (-7/1)  - ( -2/11 : ( 4/5 ) ]

  [   1/5*7 - (- 2/11 : 4/5 ) ]

  [   7/5 - ( -2/ 11 : 4/ 5 ) ]

  [  7/5  + 2/11 : 4/5 ]

 [  7/5 + 2/11 * 5/4 ]

 [7/5 + 1/11 * 5/2 ]

 [ 7/5 +  5 / 22 ]

  22 * 7 + 5 * 5

-----------------------

        110

  154+ 5*5               154+25            179

----------------  =   -----------------  =  ----------

       110                   110                  110