计算(1−122)(1−132)…(1−192)(1−1102)=( ) A.1021 B.1321 C.920 D.1120
问题描述:
计算(1−
)(1−1 22
)…(1−1 32
)(1−1 92
)=( )1 102
A.
10 21
B.
13 21
C.
9 20
D.
11 20
答
原式=(1-
)(1+1 2
)×(1-1 2
)(1+1 3
)×…×(1-1 3
)×(1+1 9
)×(1-1 9
)×(1+1 10
),1 10
=
×1 2
×3 2
×2 3
×…×4 3
×8 9
×10 9
×9 10
,11 10
=
.11 20
故选D.