Giúp mình với:
Tính:
1/2003*2002 - 1/2002*2001 - 1/2001*2000 - ... - 1/2*1
Những câu hỏi liên quan
A= 1/2003×2002 - 1/2002×2001- 1/2001×2000- .....-1/3×2- 1/2×1
tính: 1/2000+2001+1/2001+2002+1/2002+2003+...+1/2009+2010
=1/2000-1/2001+1/2001-1/2002+1/2002-1/2003+......+1/2009-1/2010
=1/2000-1/2010
=1/402000
Đúng 0
Bình luận (0)
\(\frac{1}{2000+2001}+\frac{1}{2001+2002}+\frac{1}{2002+2003}+...+\frac{1}{2009+2010}\)
\(=\frac{1}{2000}-\frac{1}{2001}+\frac{1}{2001}-\frac{1}{2002}+\frac{1}{2003}-\frac{1}{2003}+...+\frac{1}{2009}-\frac{1}{2010}\)
\(=\frac{1}{2000}-\frac{1}{2010}\)
\(=\frac{1}{402000}\)
Đúng 0
Bình luận (0)
tính: 1/2000+2001+1/2001+2002+1/2002+2003+...+1/2009+2010
\(\frac{1}{2000}\)+2001+\(\frac{1}{2001}\)+ 2002+\(\frac{1}{2002}\)+2003+...+\(\frac{1}{2009}\)+2010
2001,0005+2002,0005+2003,0005+...+2010,0005
Số số hạng là:
(2010,0005-2001,0005)+1=10( số)
Số cặp số hạng là:
10:2= 5 ( cặp)
Tổng từng cặp là: 2001,0005+2010,0005=2002,0005+2009,0005=...=4011,001
Tổng của các số hạng trên là :
4011,001x5=20055,005
Đúng 0
Bình luận (0)
\(\frac{1}{2000+2001}+\frac{1}{2001+2002}+\frac{1}{2002+2003}+...+\frac{1}{2009+2010}\)
\(=\frac{1}{2000}-\frac{1}{2001}+\frac{1}{2002}-...+\frac{1}{2009}-\frac{1}{2010}\)
\(=\frac{1}{2000}-\frac{1}{2010}\)
\(=\frac{1}{402000}\)
Đúng 0
Bình luận (0)
1/2002+(2003*2001/2002)-2003/1
Trả lời giúp mình nha! Cảm ơn.
1/(x+2000)(x+2001) + 1/(x+2001)(x+2002) +1/(x+2002)(x+2003) +........+ 1/(x+2006)(x+2007)= 7/8
(x+4/2000)+(x+3/2001)=(x+2/2002)+(x+1/2003)
tìm x giúp mình nha
Ta có: \(\left(\frac{x+4}{2000}\right)+\left(\frac{x+3}{2001}\right)=\left(\frac{x+2}{2002}\right)+\left(\frac{x+1}{2003}\right)\)
\(\Rightarrow\left(\frac{x+4}{2000}+1\right)+\left(\frac{x+3}{2001}+1\right)=\left(\frac{x+2}{2002}+1\right)+\left(\frac{x+1}{2003}+1\right)\)
\(\Rightarrow\frac{x+2004}{2000}+\frac{x+2004}{2001}=\frac{x+2004}{2002}+\frac{x+2004}{2003}\)
\(\Rightarrow\left(x+2004\right).\left(\frac{1}{2000}+\frac{1}{2001}-\frac{1}{2002}+\frac{1}{2003}\right)=0\)
Vì \(\frac{1}{2000}+\frac{1}{2001}-\frac{1}{2002}+\frac{1}{2003}\ne0\)
=> x + 2004 =0
=> x = -2004
Đúng 3
Bình luận (0)
So sánh : a) A = 2001 + 2002 / 2002 + 2003 và B = 2001/2002 + 2002/ 2003
b) A = 2006^2006 + 1/2006^2007 +1 và B = 2006^2005 + 1/2006^2006 + 1
c ) A = 1999^1999 + 1/1999^2000 + 1 và B = 1999^1989 + 1/1999^2009 + 1
B = \(\frac{2001}{2002}+\frac{2002}{2003}\)
có: \(\frac{2000}{2001}>\frac{2000}{2001}+2002\)
\(\frac{2001}{2002}>\frac{2001}{2001}+2002\)
Vậy A>B
Đúng 0
Bình luận (0)
1/(x+2001)(x+2002) +1/(x+2002)(x+2003)+(1/(x+2003)(x+2004)+.......+ 1/(x+2006)(x+2007) =7/8
giải giúp mình chi tiết nha.
x+4/2000 + x+3/2001 = x+2/2002 + x+1/2003
\(\dfrac{x+4}{2000}\) + \(\dfrac{x+3}{2001}\) =\(\dfrac{x+2}{2002}\) + \(\dfrac{x+1}{2003}\)
<=> \(\dfrac{x+4}{2000}\) + 1 + \(\dfrac{x+3}{2001}\) +1 = \(\dfrac{x+2}{2002}\) + 1 + \(\dfrac{x+1}{2003}\) + 1
<=>\(\dfrac{x+4}{2000}\)+\(\dfrac{2000}{2000}\)+\(\dfrac{x+3}{2001}\) \(\dfrac{2001}{2001}\) = \(\dfrac{x+2}{2002}\)+\(\dfrac{2002}{2002}\)+\(\dfrac{x+1}{2003}\)+\(\dfrac{2003}{2003}\)
<=> \(\dfrac{x+4+2000}{2000}\)+\(\dfrac{x+3+2001}{2001}\) = \(\dfrac{x+2+2002}{2002}\)+ \(\dfrac{x+1+2003}{2003}\)
<=> \(\dfrac{x+2004}{2000}\) + \(\dfrac{x+2004}{2001}\) - \(\dfrac{x+2004}{2002}\) - \(\dfrac{x+2004}{2003}\) = 0
<=> (x+2004)(\(\dfrac{1}{2000}\) + \(\dfrac{1}{2001}\) - \(\dfrac{1}{2002}\) -\(\dfrac{1}{2003}\)) = 0
mà \(\dfrac{1}{2000}\) + \(\dfrac{1}{2001}\) - \(\dfrac{1}{2002}\) - \(\dfrac{1}{2003}\) khác 0
nên x+2004=0
=>x=0-2004
=> x = -2004
vậy S = -2004.
Tick nha
Đúng 0
Bình luận (0)