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7分之5*11分之6*7/10 3/4*(9/10%5/6) (1/5+1/9...

(9分之8+1又7分之3+10分之6)除以(11分之3+7分之5+9分之4) =(8/9+10/7+6/10)除以(3/11+5/7+4/9) =(560/630+900/630+378/630)除以(189/693+495/693+308/693) =(1838/630)除以(993/693) =(1838/630)X(693/993) =(919/105)X(...

1+9=10,2+8=10,3+7=10,4+6=10,所以=10+10+10+10+10+5=55

这个题主要就是要注意:圆括号,加号、减号、乘号与取余的优先级与结合性。 其中,圆括号优先级最高,乘号和取余第二,加号和减号最低 结合性均是从左到右。 10 + 9 * ((8 + 7) % 6) + 5 * 4 % 3 * 2 + 3 =10 + 9 * (15% 6) + 5 * 4 % 3 * 2 + 3...

1/1*2*3+1/2*3*4+1/3*4*5+1/4*5*6+1/5*6*7+1/6*7*8+1/7*8*9+1/8*9*10+1/9*10*11 =(1/2)[(1/1*2)-(1/2*3)]+(1/2)[(1/2*3)-(1/3*4)]+(1/2)[(1/3*4)-(1/4*5)]+...+(1/2)[(1/9*10)-(1/10*11)] =(1/2)[(1/1*2)-(1/2*3)+(1/2*3)-(1/3*4)+(1/3*4)-(1/4*...

1x2/3x2+3x4/5x4+5x6/7x6+7x8/9x8+9x10/11x10=168.2435786

将四个数字看成一组 (1+2-3-4)+(5+6-7-8)+……+(2005+2006-2007-2008) =(-4)+(-4)+…+(-4) =(-4)*(2008/4) =-2008 这里2008/4是因为一共有2008个数,每四个数一组,当然就是2008/4组数了,每组都是-4,两者相乘即可

裂项法: 2*3/1*4+5*6/4*7+8*9/7*10+11*12/10*13+……+2012*2013/2011*2014 =1+2/1*4+1+2/4*7+1+2/7*10+1+2/10*13+……+1+2/2011*2014 =671+2/3*(1-1/4+1/4-1/7+1/7-1/10+1/10-1/13+……+1/2011-1/2014) =671+2/3*(1-1/2014) =671+2/3*2013/2014 =...

1/[n(n+1)(n+2)]=1/2*[1/n-2/(n+1)+1/(n+2)], 例如 ∴1/(1*2*3)+1/(2*3*4)+1/(3*4*5)+1/(4*5*6)+1/(5*6*7)+1/(6*7*8)+1/(7*8*9) =1/2*[1-2/2+1/3+1/2-2/3+1/4+1/3-2/4+1/5+……+1/7-2/8+1/9] =1/2[1-1/2-1/8+1/9] =1/2(1/2-1/72) =35/144. 后面加一...

9分之8加1又7分之3加11分之6的和除以11分之3加7分之五加9分之4的和 =(8/9+10/7+6/11)/(3/11+5/7+4/9) =2*(4/9+5/7+3/11)/(3/11+5/7+4/9) =2

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