(1/2-3+5/6-7/12)×(-36)
问题描述:
(1/2-3+5/6-7/12)×(-36)
(2又1/3-238/54+91/117)×(-1又2/7)
3.228×(-9)+(-3.772)×9-(-1.5×9)
(1-1/2)(1/3-1)(1-1/4)(1/5-1)…(1/2009-1)(1-1/2010)
答
1/2-3+5/6-7/12)×(-36)=(-5/2+3/12)×(-36)=(-10+1)/4)×(-36)
=-9×(-9)=81
(1-1/2)(1/3-1)(1-1/4)(1/5-1)…(1/2009-1)(1-1/2010)
=1/2×(-2/3)×3/4×(-4/5)…(-2008/2009)(2009/2010)=1/2010