计算:(要求写出计算过程)(1) 13 4 19 +86 15 19 ×0.25+0.625×86 15 19 +86

1个回答

  • (1)13

    4

    19 +86

    15

    19 ×0.25+0.625×86

    15

    19 +86

    15

    19 ×

    1

    8 ,

    =13

    4

    19 +86

    15

    19 ×(

    1

    4 +

    5

    8 +

    1

    8 ),

    =13

    4

    19 +86

    15

    19 ×1,

    =100;

    (2)(

    1

    2 +1

    1

    12 )÷2

    1

    9 ÷(2-0.25),

    =(

    6

    12 +1

    1

    12 )×

    1

    19 ÷

    7

    4 ,

    =

    19

    12 ×

    1

    19 ×

    4

    7 ,

    =

    1

    12 ×

    4

    7 ,

    =

    1

    21 ;

    (3)2-

    6

    13 ÷

    9

    26 -

    2

    3 +

    8

    15 ÷0.6×

    2

    3 ,

    =2-

    6

    13 ×

    26

    9 -

    2

    3 +

    8

    15 ÷

    3

    5 ×

    2

    3 ,

    =2-

    4

    3 -

    2

    3 +

    8

    15 ×

    5

    3 ×

    2

    3 ,

    =2-(

    4

    3 +

    2

    3 )+

    16

    27

    =0 +

    16

    27 ,

    =

    16

    27 ;

    (4)2008×1

    1

    2 ÷1

    1

    3 -100

    2

    5 ÷

    1

    20 ,

    =2008×

    3

    2 ×

    3

    4 -

    502

    5 × 20,

    =502×

    9

    2 -502×4,

    =502×(

    9

    2 -

    8

    2 ),

    =502×

    1

    2 ,

    =251.