问题
填空题
设N=99999.则N3=______.
答案
∵N=99999+1-1=105-1,
∴N3=(105-1)3=1015-3×1010+3×105-1=1010(105-3)+3×105-1=99997000000+299999=999970000299999.
故答案是999970000299999.
设N=99999.则N3=______.
∵N=99999+1-1=105-1,
∴N3=(105-1)3=1015-3×1010+3×105-1=1010(105-3)+3×105-1=99997000000+299999=999970000299999.
故答案是999970000299999.