2^2010-(2^2009+2^2008+2^2007+......+2^1+2^0)
Tính:\(^{1^2}\)
a) 1^2-2^2+3^2-4^2+5^2-6^2+....+2009^2-2010^2
b) 3^2010-(3^2009+3^2008+3^2007+...+3+3^0)
2. So sánh A và B:
A= 2006/2007 - 2007/2008 + 2008/2009 - 2009/2010
B=-1/2006*2007 - 1/2008*2009
tính tổng sau :\(c=\frac{\frac{1}{2008}-\frac{1}{2009}-\frac{1}{2010}}{\frac{5}{2008}-\frac{5}{2009}-\frac{5}{2010}}+\)\(\frac{\frac{2}{2007}-\frac{2}{2008}-\frac{2}{2009}}{\frac{3}{2007}-\frac{3}{2008}-\frac{3}{2009}}\)
\(C=\frac{\frac{1}{2008}-\frac{1}{2009}-\frac{1}{2010}}{\frac{5}{2008}-\frac{5}{2009}-\frac{5}{2010}}+\frac{\frac{2}{2007}-\frac{2}{2008}-\frac{2}{2009}}{\frac{3}{2007}-\frac{3}{2008}-\frac{3}{2009}}\)
\(=\frac{\frac{1}{2008}-\frac{1}{2009}-\frac{1}{2010}}{5.\left(\frac{1}{2008}-\frac{1}{2009}-\frac{1}{2010}\right)}+\frac{2.\left(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\right)}{3.\left(\frac{1}{2007}-\frac{1}{2008}-\frac{1}{2009}\right)}\)
\(=\frac{1}{5}+\frac{2}{3}\)
\(=\frac{13}{15}\)
2^2010-2^2009-2^2008-2^2007-....-2-1
So sánh
bài 1 :A= 2006/2007-2007/2008+2008/2009-2009/2010
B= -1/2006*2007-1/2008*2009
bài 2: C= 2006/2007+2007/2008+2008/2009+2009/2006 với 4
Tính: M=22010-(22009+22008+22007+...+21+20).
M=2^2010-(2^2009+2^2008+2^2007+...+2^1+2^0)
M=22010-22009-22008-22007-...-21-20
=>2M=22011-22010-22009-22008-...-22-21
=>2M-M=22011-22010-22009-22008-...-22-21-(22010-22009-22008-22007-...-21-20)
=>M=22011-22010-22009-22008-...-22-21-22010+22009+22008+22007+...+21+20
=22011-22010-22010+20
=22011-2.22010+1
=22011-22011+1
=1
vậy M=1
đúng mjk với nha
ĐẶt A = 2^0 + 2^1 +.. + 2^2009
2A = 2^ 1 + 2^2 +.... + 2^2009 +2 ^2010
2A - A = 2^1 + 2^2 + . ... + 2^2009 +2^2010 - 2 ^0 - 2^1 - 2^2 -..-2^3009
A = 2^2010 - 2^0 = 2^2010 - 1
M = 2^2010 - A = 2^2010 - (2^2010 - 1) = 2^2010 - 2^2010 +1 = 1
Giải :
M = 22010 - ( 22009 + 22008 + 22007+.......+ 21 + 20 )
<=>M = 22010 - 22009 - 22008 - 22007 -.......- 21 - 20
=> 2M = 22011 - 22010 - 22009 - 22008 -.......- 22 - 21
=> 2M - M = M = 22011 - 20
=> M = 22011 - 1
Vậy: M = 2 2011 - 1.
M=22010-(22009+22008+22007+...+21+20)
M = 22010 - ( 22009 + 22008 + 22007 + ... + 21 + 20)
Ta có: N = 22009 + 22008 + 22007 + ... + 21 + 20
2N = 22010 + 22009 + 22008 + ... + 22 + 21
N = 2N - N = ( 22010 + 22009 + 22008 + ... + 22 + 21) - ( 22009 + 22008 + 22007 + ... + 21 + 20 )
N = 22010 - 20
Suy ra: M = 22010 - 22010 - 20
M = 0 - 1
M = -1
Vậy M = -1
tính M=22010 - (22009+22008+22007+..........+20)
M=2^2010-(2^2009+2^2008+2^2007+...+2^1+2^0)
M=22010-22009-22008-22007-...-21-20
=>2M=22011-22010-22009-22008-...-22-21
=>2M-M=22011-22010-22009-22008-...-22-21-(22010-22009-22008-22007-...-21-20)
=>M=22011-22010-22009-22008-...-22-21-22010+22009+22008+22007+...+21+20
=22011-22010-22010+20
=22011-2.22010+1
=22011-22011+1
=1
Vậy........
Tính
1/1*2+1/3*4+1/4*5+1/5*6+.......+1/99*100
\(C=\frac{2010+\frac{2009}{2}+\frac{2008}{3}+...+\frac{2}{2007}+\frac{1}{2008}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...\frac{1}{2008}+\frac{1}{2009}}.\)
có nhầm đề không vậy phải là 2010-