1999/（1999+1999/2000）+1/2

1999/（1999+1999/2000）+1/2000等于多少?

5个回答

应该是1999/（1999+1999/2000）+1/2001
=1999/[1999×(1+1/2000)]+1/2001
=1/(1+1/2000)+1/2001
=2000/2001+1/2001
=1