F = 1 + 2 + 3 + ...+ 2002 + 2003 + 2005
Số số hạng là:
(2005-1):1+1=2005 (ssh)
F là:
(2005+1)x2005:2=2011015
\(F=\frac{\left(1+2003\right)\cdot2003}{2}+2005=2009011\)
f=1-2-3+4+5-6-7+8+9-...+2001-2002-2003+2004+2005
Tinh hợp lý các biểu thức sau:
F=1-2+3-4+....+2009+2010
G=0-2+4-6+...+2010-2010
H=13-12+11+10-9+8-7-6+5-4-3+2-1
I=1-2-3+4+5-6-7-8+9...+2001-2002-2003+2004+2005+2006
J=1+2-3-4+6+6-7-8+9+...+2002-2003-2004+2005+2006
P=1/2003+1/2004-1/2004 - 2/2002+2/2003-2/2004
5/2003+5/2004-5/2005 3/2002+3/2003-3/2004
BT
a,,A=48+|48-174|+(-74)
b,,B=1-2+3-4+...+2009-2010
c,,C=0-2+4-6+...+2010-2012
d,,D=13-12+11+10-9+8-7-6+5-4+3+2-1
e,,E=1-2-3+4+5-6-7+8+...+2001-2002-2003+2004
f,,F=1+2-3-4+5-6-7+8+...+2002-2003-2004+2005+2006
Tính các tổng:
1/ S = 1 - 2 - 3 + 4 + 5 - 6 - 7 + 8 + ...+ 2001- 2002 - 2003 + 2004
2/ S = 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + ...+ 2002 - 2003 - 2004 + 2005 + 2006
tính : a)1-2-3+4+5-6-7+8+...+2001-2002-2003+2004
b)1+2-3-4+5+6-7-8+9+...+2002-2003-2004+2005+2006
Bài 2. Tính:
a) A = 1 – 2 – 3 + 4 + 5 – 6 – 7 + 8 + ... + 2001 – 2002 – 2003 + 2004.
b) B = 1 + 2 – 3 – 4 + 5 + 6 – 7 – 8 + 9 + ... + 2002 – 2003 – 2004 + 2005 + 2006.Mik sẽ tick cho bạn trả lời nha
tính nhanh ; S = 1 + 2 + 3+ ... + 2002 + 2003 + 2005
A=1-3+5-7+...+2001-2003+2005
B=1-2-3+4+5-6-7+8+...+1993-1994
C=1+2-3-4+5+6-7-8+9+...+2002-2003-2004+2005+2006
