31 1/3*41 1/2 -11 1/3*41 1/2*2-9 1/2*11 1/3
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31 1/3*41 1/2 -11 1/3*41 1/2*2-9 1/2*11 1/3
![31 1/3*41 1/2 -11 1/3*41 1/2*2-9 1/2*11 1/3](/uploads/image/z/18423829-37-9.jpg?t=31+1%2F3%2A41+1%2F2+-11+1%2F3%2A41+1%2F2%2A2-9+1%2F2%2A11+1%2F3)
31 1/3*41 1/2 -11 1/3*41 1/2*2-9 1/2*11 1/3
=94/3*83/2-34/3*83/2*2-19/2*34/3
=1/6(94*83-34*83-34*83-19*34)
=1/6[83*(94-34)-34*(83+19)]
=1/6(83*60)-1/6(34*102)
=83*10-34*17=830-578=252
=94/3*83/2-34/3*83/2*2-19/2*34/3
=1/6(94*83-34*83-34*83-19*34)
=1/6[83*(94-34)-34*(83+19)]
=1/6(83*60)-1/6(34*102)
=83*10-34*17=830-578=252
9×0+1=1 9×1+2=11 9×2+3=21 9×3+4=31 9×4+5=41 … 猜想
31又3分之1×41又2分之1减11又3分之1×41又2分之1×2减9.5×11又3分之1的简算
简便计算?51 2/3+41 1/3*3/4+31 1/2*2/3
找规律:(1):3,9,11,17,20,( ),( ),36,41,(… (2):1,3,2,6,4,( ),( ),
找规律 (1)3,9,11,17,20, , ,36,41,…… (2)1,3,2,
1 {1/11+1/21+1/31+1/41}*{1/21+1/31+1/41+1/51}-{1/11+1/21+1/3
(1/11+1/21+1/31++1/41)*(1/21+1/31++1/41+1/51)-(1/11+1/21+1/3
41) 1/5(1-1/3×1/2)
(1)3,9,11,17,20,(),()36,41,47.(2)1,4,9,16,(),()49,64,(),100.
9×0+1=1,9×1+2=11,9×2+3=21,9×3+4=31,9×4+5等于41,……猜想第n个等式(n为正整数
如果定义:11=1,21=1×2,31=1×2×3,41=1×2×3×4,……1001=1×2×3×4×5×6……×99
1/1*3+1/5*7+ 1/9*11+.1/(2n-1)(2n+1)