9/1x3+9/3x5+9/5x7+.+9/2005x2007=
1个回答
9/[n*(n+2)]=(9/2)*{(1/n)-[1(n+2)]}
用这个公式每项将原式化简
结果是(9/2)*(2006/2007)
相关问题
1.(7X-3X+5.9)/3=2.9
7/9x(-8/9)+2/9x(-8/9) 2/3x(-5/8)-(-1/3)x(-5/8) -9除以3+(1/2-2/
8x+5x=1.3 4.5x-3.2x=3.9 5.5x-x=9.9 11x-7x-26=34 列方程
3X(3)+5X(2)=9,7X(3)+9X(2)=7
X+3.5X=9.9怎么解X+3.5X=9.94.5X=9.9X=2.2
5/35 X 4/9 + 4/7 X 6/9 1.2/9 - 2/9 X 3/10 2.5/35 X 4/9 + 4/7
1/1x3+1/3x5+1/5x7+1/7x9+1/9x11+1/11x13=
(x+1)(x+3)(x+5)(x+7)-9
1+3+5+7+9+...+2003+2005+2007=?
第一道 (X+2)^9=A0+A1*X+A2*X^2+A3*X^3+.+A9*X^9求(A1+3A3+5A5+7A7+9