(﹣1×1/2﹚+﹙﹣1/2×1/3﹚+﹙﹣1/3×1/4﹚+……+﹙﹣1/2008×1/2009﹚
我要过程
原式=-(1-1/2+1/2-1/3+1/3-1/4.....-1/2009)
=-(1-1/2009)
=-2008/2009