tính tổng đại số sau đây: a)1-2-3+4+5-6-7+….+1996+1997-1998-1999+2000+20001 23/07/2021 Bởi Katherine tính tổng đại số sau đây: a)1-2-3+4+5-6-7+….+1996+1997-1998-1999+2000+20001
` a) ` ` 1 – 2 – 3 + 4 + 5 – 6 – 7 + … + 1996 + 1997 – 1998 – 1999 + 2000 + 20001 ` ` =(1-2-3+4)+(5-6-7+8)+…+(1997-1998-1999+2000)+20001 ` ` =0+20001 ` ` =20001 ` Bình luận
a, 1-2-3+4+5-6-7+….+1996+1997-1998-1999+2000+20001 =(1-2-3+4)+(5-6-7+8)+…+(1997-1998-1999+2000)+20001 =0+0+…+0+20001 =20001 Bình luận
` a) ` ` 1 – 2 – 3 + 4 + 5 – 6 – 7 + … + 1996 + 1997 – 1998 – 1999 + 2000 + 20001 `
` =(1-2-3+4)+(5-6-7+8)+…+(1997-1998-1999+2000)+20001 `
` =0+20001 `
` =20001 `
a, 1-2-3+4+5-6-7+….+1996+1997-1998-1999+2000+20001
=(1-2-3+4)+(5-6-7+8)+…+(1997-1998-1999+2000)+20001
=0+0+…+0+20001
=20001