初二数学计算题(用简便方法计算)
- 来源:互联网
- 发布时间:2026-05-04 13:40:21
解:原式=(1+1/2)(1-1/2)(1+1/3)(1-1/3).....(1+1/9)(1-1/9)(1+1/10)(1-1/10)
=1/2*3/2*2/3*4/3*.....*8/9*10/9*9/10*11/10
=1/2*11/10
=11/20
解:原式=(1+1/2)(1-1/2)(1+1/3)(1-1/3).....(1+1/9)(1-1/9)(1+1/10)(1-1/10)
=1/2*3/2*2/3*4/3*.....*8/9*10/9*9/10*11/10
=1/2*11/10
=11/20