计算下面各题,注意使用简便运算.

1个回答

  • (1)

    4

    9 ×

    1

    5 ÷

    4

    5 ,

    =

    4

    9 ×

    1

    5 ×

    5

    4 ,

    =

    1

    9 ;

    (2)

    4

    5 ÷

    2

    3 ÷

    5

    6 ,

    =

    4

    5 ×

    3

    2 ×

    6

    5 ,

    =

    36

    25 ;

    (3)(15-14×

    4

    7 )×

    8

    21 ,

    =(15-8)×

    8

    21 ,

    =7×

    8

    21 ,

    =

    8

    3 ;

    (4)

    2

    7 ×

    8

    9 +

    5

    7 ×

    8

    9 ,

    =(

    2

    7 +

    5

    7 )×

    8

    9 ,

    =1×

    8

    9 ,

    =

    8

    9 ;

    (5)

    4

    5 ÷[(

    1

    3 +

    2

    5 )×

    4

    11 ],

    =

    4

    5 ÷[

    11

    15 ×

    4

    11 ],

    =

    4

    5 ÷

    4

    15 ,

    =

    4

    5 ×

    15

    4 ,

    =3;

    (6)

    7

    5 -

    5

    8 -

    9

    16 ÷

    3

    2 ,

    =

    7

    5 -

    5

    8 -

    9

    16 ×

    2

    3 ,

    =

    7

    5 -

    5

    8 -

    3

    8 ,

    =

    7

    5 -(

    5

    8 +

    3

    8 ),

    =

    7

    5 -1,

    =

    2

    5 .