巧算一列数 1/2+1/4+1/6+1/8+1/12+1/18+1/24

原式=1法可比结讨想杆措/(1*2)+1/(2来自*3+1/(3*4兵巴它)+1/4+1/2*(1/4+1/9+1/(3*4))
=1-1/2+1/2-1/3+1/3输硫-1/4+1/4+1/2*(1/4+1/9+1/3-1/4)
=1+1/2*(1/9+1/3)
=1+2/9
=11/9