绅宝x65停产 (1/3xo.1875十1/400)x65(简算)
(1/3xo.1875十1/400)x65(简算)
(1/3xo.1875十1/400)x65(简算)
(1/3 * 0.1875 + 1/400) * 65
= (1/3 * 1875/10000 + 1/400)*65
=( 1/3 * 75/400 + 1/400) * 65
=(25/400 + 1/400)*65
=(26/400) * 65
=(26 * 65 / 400)
= (13 * 13 /40)
= 169/40
= 4(9/40)
36x(1/3x1/4x1/6)简算
原式=36x1/(3x4x6)
=36x1/72
=36/72
=1/2
2/3x1/6除以(1/2—1/6)怎样简算
=(2/3*1/6)/(1/2)-(2/3*1/6)/(1/6)
=2/9-2/3
=2/9-6/9
=-4/9
3x4x5x(1/3十1/4十1/5)能简便算吗
原式
=3x4x5x1/3+3x4x5x1/4+3x4x5x1/5
=1x4x5+3x1x5+3x4x1
=20+15+12
=47
供参考。
78x(1/31一1/47)+31x(1/47十1/78)一47x(1/31一1/78)简算
78x(1/31一1/47)+31x(1/47十1/78)一47x(1/31一1/78)
=78/31-78/47+31/47+31/78-47/31+47/78
=78/31-47/31-78/47+31/47+31/78+47/78
=31/31-47/47+78/78
=1-1+1
=1
2÷(1/3十1/7)怎样简算?
2÷(1/3十1/7)
=2×21÷(1/3×21+1/7×21)
=42÷(7+3)
=42÷10
=4.2
1/1X2+1/2X3+1/3X4……+1/99X100=???简算
1/n(n+1)=1/n-1/(n+1)
1/1X2+1/2X3+1/3X4……+1/99X100=1/1-1/2+1/2-1/3+……+1/99-1/100
=1-1/100
=0.99
简算:1/(1*3)+1/(3*5)+1/(5*7)+……+1/(99*101)=
普遍适用的通式可以写成
1/[(2k-1)*(2k+1)]=1/2[1/(2k-1)-1/(2k+1)]
分别把1,2,3……50代入就得到
1/(1*3)=1/2(1/1-1/3)
1/(3*5)=1/2(1/3-1/5)
……
1/(99*101)=1/2(1/99-1/101)
在把上面的50个式子相加
左边就是你要求的表达式
右边提出1/2后可以约掉大部分项,最后只剩第一项和最后一项
结果为
1/2(1-1/101)=50/101
24又1/13x1/2的简算
24又1/13 x 1/2
=(24+1/13)x 1/2
=24 x 1/2 +1/13 x 1/2
=12+1/26
=12又26分之1

简算:1/1x3+1/3x5+1/5x7+…+1/17x19+1/19x21
1/1X3+1/3X5+1/5X7+......+1/17X19+1/19X21
=(2/1X3+2/3X5+2/5X7+......+2/17X19+2/19X21 )÷2
=(1/1-1/3+1/3-1/5+1/5-1/7+.............+1/17-1/19+1/19-1/21)÷2
=(1-1/21)÷2
=10/21
因为1/(2n-1)-1/(2n+1)=2/[(2n-1)(2n+1)]
例如:1/3-1/5=2/(3×5)