0.47乘1.2 0.86乘1.2-1.33乘0.2
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等于30414093201713378043612608166064768844377641568960512000000000000
1,=(1/2)×(1/1×2+1/2×3)+(1/2)×(1/2×3-1/3×4)+……+(1/2)×(1/48×49-1/49×50)=(1/2)×(1/1×2+1/2×3+1/2×3-1/3×4
0.36乘5.3+3.6乘0.47=3.6乘0.53+3.6乘0.47=3.6×(0.53+0.47)=3.6
原式=1/2*(1/2*3-1/3*4+1/3*4-1/4*5+.+1/8*9-1/9*10)=1/2*(1/6-1/90)=1/2*(14/90)=7/90
274×150+950×822=822×50+950×822=822×(50+950)=820×1000=820000153×46+71×54+82×54=153×46+(71+82)×54=153×
再问:98乘97分之5再答:嗯,等下再答:
2*3+5*9行不?
56乘1.25=7x8x1.25=7x10=70如果本题有什么不明白可以追问,请及时点击右下角的【采纳为满意回答】按钮再问:就那么简单?
答案4949/19800.n×(n+1)×(n+2)分之一=1/2{1/n×1/(n+1)-1/(n+1)×1/(n+2)}按上面式子每项裂开,消去之后,变成=1/2{1/2-1/9900},完毕
4949/19800因为1/n(n+1)(n+2)=1/n(1/(n+1)-1/(n+2))=1/n-1/(n+1)-1/2(1/n-1(n+1))
43×126-86×13=43×126-43×13×2=43×(126-26)=43×100=4300
原式=(1-1/2)+(1/2-1/3)+(1/3-1/4)+……+(1/2012-1/2013)=1-1/2+1/2-1/3+1/3-1/4+……+1/2012-1/2013中间部分抵消了=1-1/
86x584-84x586=(84+2)x584-84x(584+2)=84x584+2x584-84x584-84x2=2x584-84x2=(584-84)x2=500x2=1000
N!=N*(N-1)*(N-2)*...3*2*1N!=N*(N-2)*(n-4)*...N!=N*(N-3)*(N-6)*...1乘4乘7乘10乘13乘...乘697乘700等于700!
1乘2乘3乘4乘5乘6乘7乘8=40320
988×87-989×86=988×87-(988+1)×86=988×87-988×86-1×86=988×(87-86)-86=988×1-86=988-86=902很高兴为您解答,【the190
!表示阶乘所以100!/98!=100*99*98*97*96*……*1/98/97/96/……/1=100*99=9900
0.13乘0.47乘1.8=0.13*(0.5-0.03)(2-0.2)=0.13*(1-0.1-0.06+0.006)=(0.1+0.03)*0.846=0.0846+0.02538=0.10998
解题思路:考查幂的运算解题过程:解:(1)第一次撕成2片,即21;第二次撕成4片,即22;....所以第n次撕成2n,则2n=64所以n=6所以要把这张纸撕成64片需要6次(2)撕7次后这张纸变成27