题错了,应该是99999×77778
99999×77778+33333×66666
=99999×77778+33333×3×22222
=99999×77778+99999×22222
=99999×(77778+22222)
=99999×100000
=9999900000
99999+77778+33333×66666
=99999+77778+99999×22222
=100000-1+99999×(77778+2222)
=100000-1+99999×100000
=100000×(1+99999)-1
=100000×100000-1
=10000000000-1
=9999999999
99999×77778+33333×66666
=99999×77778+33333×3×22222
=99999×77778+99999×22222
=99999×(77778+22222)
=99999×100000
=9999900000
=9999900000