计算题999…99 × 999…99 +1999…99
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计算题999…99 × 999…99 +1999…99
计算999…99 × 999…99 +1999…99 后所得的末尾有( )个零.
(1992个)(1992个)(1992个)
计算999…99 × 999…99 +1999…99 后所得的末尾有( )个零.
(1992个)(1992个)(1992个)
计算999…99 × 999…99 +1999…99 后所得的末尾有( 1992×2 = 3984 )个零.
(1992个)(1992个)(1992个)
将“000...0000(1992个0)”缩写为“A”,则原式为:
999…99 × 999…99 +1999…99
=(1A -1)(1A -1) +2A-1
=1A × 1A - 2A +1 +2A-1
=1A × 1A
即:
100...0 × 100.0
(1992个) 1992个
结果为100..00
3984个
(1992个)(1992个)(1992个)
将“000...0000(1992个0)”缩写为“A”,则原式为:
999…99 × 999…99 +1999…99
=(1A -1)(1A -1) +2A-1
=1A × 1A - 2A +1 +2A-1
=1A × 1A
即:
100...0 × 100.0
(1992个) 1992个
结果为100..00
3984个