计算下面各题,能简算的要简算. 3 4 : c 6 =x: 5 3 9 x = 6 0.5 x:0.1c=3.6: 9

1个回答

  • (1)

    3

    一 :

    5

    n =x:

    2

    3 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;

    5

    n x=

    3

    一 ×

    2

    3 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;

    5

    n x=

    1

    2 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;

    5

    n x ÷

    5

    n =

    1

    2 ÷

    5

    n ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; x=

    3

    5 ;

    (2)

    9

    x =

    n

    0.2 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三; nx=9×0.2,

    &nbs三;&nbs三;&nbs三;nx÷n=1.8÷n,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; x=0.3;

    (3)x:0.15=3.n:

    9

    10 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;

    9

    10 x=0.15×3.n,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;

    9

    10 x=0.5一,

    &nbs三;&nbs三;&nbs三;

    9

    10 x ÷

    9

    10 =0.5一÷

    9

    10 ,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; x=0.n;

    (一)3:

    3

    一 =12:x,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; 3x=

    3

    一 ×12,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; 3x=9,

    &nbs三;&nbs三;&nbs三;&nbs三; 3x÷3=9÷3,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; x=3;

    (5)1一×3+7x=5n,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; 一2+7x=5n,

    &nbs三;&nbs三;&nbs三;&nbs三; 一2+7x-一2=5n-一2,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; 7x÷7=1一÷7,

    &nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三;&nbs三; x=2;

    (n)3.5×9.8+3.5×0.2,

    =3.5×(9.8+0.2),

    =3.5×10,

    =35;

    (7)

    7

    9 ÷

    11

    5 +

    2

    9 ×

    5

    11 ,

    =

    5

    11 ×(

    7

    9 +

    2

    9 ),

    =

    5

    11 ×1,

    =

    5

    11 ;

    (8)

    1

    3 ÷(

    2

    3 -

    2

    5 )×

    3

    5 ,

    =

    1

    3 ÷

    15 ×

    3

    5 ,

    =

    5

    一 ×

    3

    5 ,

    =

    3

    一 .