脫式計算 能用簡便方法的要用簡便方法 八分之五 二十四分之一十三 十六分之七

2021-03-30 12:29:12 字數 5381 閱讀 7597

1樓:匿名使用者

5/8+(13/24-7/16)

=5/8+26/48-21/48

=30/48+5/48

=35/48

脫式計算題(能簡便的要用簡便方法計算)

2樓:匿名使用者

2.5×

0.32×125

=(2.5×0.4)×(0.8×125)

=1×100

=100

907×99+907

=907×(99+1)

=907×100

=90700

(1/3+1/4+1/5)×60

=(1/3)×60+(1/4)×60+(1/5)×60=20+15+12

=47[(1/7)-(1/9)]×63-(2/3)=(1/7)×63-(1/9)×63-(2/3)=9-7-(2/3)

=1又1/3

(3/5)×[(2/8)×2-(1/3)]=(3/5)×[(1/2)-(1/3)]

=(3/5)×(1/6)

=1/10

÷(4/5)

=×(5/4)

=(4/15)×(5/4)

=1/3

12.5×4×0.25×8

=(12.5×8)×(4×0.25)

=100×1

=100

(6/7)×125×7×8

=[(6/7)×7]×(125×8)

=6×1000

=6000

24×[(5/8)+(5/6)]-35

= 24×(5/8)+24×(5/6)-35=15+20-35

=35-35

=0(分數我用括號括起來了,寫的時候記得去掉,5/8讀作八分之五,應該看得懂吧!)

有疑問,請追問

3樓:匿名使用者

3. 09x3. 9÷26

=12. 051÷26

=0. 4635

4樓:匿名使用者

10^5x0.001=100 907x100=90700 20+15+12=47

下面的實在看不清

5樓:匿名使用者

1、(2.5*0.4)*(8*125)=1*1000=10002、907x99+907=907*(99+1)=907003、1/3*60+1/4*60+1/5*60=20+15+12=474、1/7*63-1/9*63-2/3=9-7-2/3=4/35、沒看出來怎麼簡便,只有按順序來=3/5*(1/2-1/3)=1/10

6、還是沒看出來怎麼簡便,只有按順序來=1-(1/5+1/3)/(4/5)=1-2/3=1/3

7、(12.5*8)*(4*0.25)=100*1=1008、【(6/7)*7】*(125*8)=6*1000=10009、【24*(1/8+1/6)】*5-35=(3+4)*5-35=0

脫式計算(能用簡便方法的要用簡便方法)5.5×17.3+2.7×5.54.6×(1-0.25)+0.75×5.40

6樓:楊冪臭腳笆璳

(1)5.5×17.3+2.7×5.5

=5.5×(17.3+2.7)

=5.5×20

=110;

(2)4.6×(1-0.25)+0.75×5.4=4.6×0.75+0.75×5.4

=0.75×(4.6+5.4)

=0.75×10

=7.5;

(3)0.25×1.25×0.16

=0.25×1.25×(0.2×0.8)

=(0.25×0.2)×(1.25×0.8)=0.05×1

=0.05;

(4)12.5×1.7+9.3×12.5-12.5=12.5×(1.7+9.3-1)

=12.5×10

=125.

脫式計算.(能用簡便方法計算的要用簡便方法計算) (1)13.6×3-40.6÷2 (2

7樓:風子

(bai1)13.6×

du3-40.6÷2,

zhi=40.8-20.3,

=20.5;dao

(2)99×0.75+1 4

×99 ,

=99×(0.75+0.25),

=99×1,

=99;

(3)(5 6

-5 8

)×24 ,

=5 6

×24-5 8

×24,

=20-15,

=5;(4)121×1001

121,

=121×(100+1

121),

=121×100+121×1

121,

=12100+1,

=12101;

(5)15÷3-7×(1 7

+1 21

) ,=15÷3-7×4

21,=5-11 3

,=32 3

;(6)246

23÷6-1

23,=41

23-1

23,=4.

脫式計算.(能用簡便方法計算的要用簡便方法計算) (1)13.6×3-40.6÷2 (2)99×0.75+14×99 (3

8樓:博

(1)13.6×

3-40.6÷2,

copy

=40.8-20.3,

=20.5;bai

(du2)99×zhi0.75+1

4×99,dao

=99×(0.75+0.25),

=99×1,

=99;

(3)(56?5

8)×24,=56

×24-5

8×24,

=20-15,

=5;(4)121×1001

121,

=121×(100+1

121),

=121×100+121×1

121,

=12100+1,

=12101;

(5)15÷3?7×(17+1

21),

=15÷3-7×421,

=5-113,

=323

;(6)246

23÷6?123,

=4123

-123

,=4.

脫式計算.(能用簡便方法的用簡便方法).3.78-1.46+1.54 17.5-5.15-1.85 4.1×9.

9樓:湛夜綠

(ⅰ)由sn=n+3

2an,①當n≥2時,sn?1=n?1+32an?1,②

兩式相減得an=1+3

2an?3

2an?1,即an=3an-1-2.當n≥2時,an?1an?1?1

=3an?1?2?1

an?1?1

=3為定值,

由sn=n+3

2an,令n=1,得a1=-2.所以數列是等比數列,公比是3,首項為-3.

所以數列的通項公式為an=1-3n.(4分)(ⅱ)∴b2=-8,b20=-80.由是等差數列,求得bn=-4n.tn=b1

a1?1

+b2a2?1

++bn?1

an?1?1

+bnan?1

=4[1

31+2

32++(n?1)

3n?1

+n3n

],而1

3tn=4[1

32+2

33++(n?1)

3n+n

3n+1

],相減得2

3tn=4(1

31+1

32++1

3n?n

3n+1

),即tn=2(1

30+1

31++1

3n?1

)?2n

3n,則tn=21?(13)n

1?13

?2n3n

=3?2n+3

3n. (8分)

∵tn+1?tn=?2n+5

3n+1

+2n+3

3n=4n+4

3n+1

>0,故遞增∴當n∈n*時,tn的最小值為43(10分)

∵不等式t

脫式計算(能用簡便方法計算的要用簡便方法計算)185-25-75 6495-(495-299) 200×4+300 9999+999+9

10樓:我是神嗷

(1)185-25-75

=185-(25+75)

=185-100

=85;

(2)6495-(495-299)

=6495-495+299

=6000+299

=6299;

(3)200×4+300

=800+300

=1100;

(4)9999+999+99+9

=(10000-1)+(1000-1)+(100-1)+(10-1)=(10000+1000+100+10)-(1+1+1+1)=11110-4

=11106.

9/14乘21乘2/9等於多少脫式計算能簡便的用簡便方法?

11樓:樂為人師

9/14乘21乘2/9等於多少脫式計算能簡便的用簡便方法?

9/14×21×2/9

=9/14×2/9×21

=1/7×21=3

12樓:數理與生活

9/14 × 21 × 2/9

= 9/2 × 3 × 2/9= 3

13樓:聽不清啊

9/14x21x2/9

=9/14x2/9x21

=1/7x21=3

脫式計算.(能用簡便方法的就用簡便方法計算)[8.5-(3.6+3.6)]÷2.6 10.1×8...

14樓:清風

(1)[8.5-(3.6+3.6)]÷

du2.6

=[8.5-7.2]÷2.6

=1.3÷2.6

=0.5;

(2)10.1×

zhi87

=(10+0.1)×87

=10×87+0.1×87

=870+8.7

=878.7;

(3)1.4×[(7.5+38.4)÷dao0.9]=1.4×[45.9÷0.9]

=1.4×51

=71.4.

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