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.
脫式計算(能用簡便方法的用簡便方法計算
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計算下面各題,能用簡便方法的要用簡便方法計算
1 9.78 2.3 2.3 10.22,9.78 10.22 2.3,20 2.3,46 2 1.5 11 7.83 3.5,16.5 7.83 3.5,8.67 3.5,12.17 3 7.25 31 29.55 1.3,7.25 1.45 1.3,5 1.3,6.5 4 75.6 0.7 8....
脫式計算,怎樣簡便就怎樣算,脫式計算,怎樣簡便就怎樣算
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