Tìm m = 2^2010 - ( 2^2009 + 2^2008 + .... + 2^1 + 2^0 )
M=2^2010-(2^2009+2^2008+...+2^1+2^0)
Tìm x thỏa mãn: x + (x + 1) + (x + 2) + … + 2009 + 2010 = 2010 A.-2010 B.-2008 C.0 D.-2009
Tính: M= 2^2010-( 2^2009 + 2^2008+....+2^1 +2^0)
Đặt N = 22009 + 22008 + 22007 +......+ 21 + 20
2N = 22010 + 22009 + 22008 +.....+ 22 + 21
2N - N = 22010 - 20
=> N = 22010 - 1
=> M = 22010 - (22010 - 1)
=> M = 22010 - 22010 + 1
=> M = 1
Tính: M=2^2010-(2^2009+2^2008+...+2^1+2^0)
Đặt N=22009+22008+...+1
=>2N=22010+22009+...+2
=>2N-N=(22010+22009+...+2)-(22009+22008+...+1)
=>N=22010-1
Mà M=22010-N=22010-(22010-1)=1
Ác Mộng trả lời đúng rùi. **** thui
Tính:
M= 2 ^2010 - (2^2009 + 2^2008 +...+ 2^1 + 2^0)
Đặt \(N=2^0+2^1+...+2^{2008}+2^{2009}\)
Suy ra: \(M=2^{2010}-N\)
Ta có: \(N=2^0+2^1+...+2^{2008}+2^{2009}\)
\(\Leftrightarrow2N=2+2^2+...+2^{2009}+2^{2010}\)
\(\Leftrightarrow N=2^{2010}-1\)
\(M=2^{2010}-N=2^{2010}-2^{2010}+1=1\)
Bài 1: cho pt \(x^2-ax+a-1=0\) có 2 no x1, x2
Tính \(M=\dfrac{2x^2_1+x_1x_2+2x_1^2}{x^2_1x_2+x^2_2x_1}\)
Bài 2: cho a,b là no pt: \(30x^2-4x=2010\)
Tình \(N=\dfrac{30\left(a^{2010}+b^{2010}\right)-4\left(a^{2009}+b^{2009}\right)}{a^{2008}+b^{2008}}\)
Bài 2:
Vì a,b là nghiệm PT nên \(\left\{{}\begin{matrix}30a^2-4a=2010\\30b^2-4b=2010\end{matrix}\right.\)
\(\Rightarrow N=\dfrac{a^{2008}\left(30a^2-4a\right)+b^{2008}\left(30b^2-4b\right)}{a^{2008}+b^{2008}}\\ \Rightarrow N=\dfrac{a^{2008}\cdot2010+b^{2008}\cdot2010}{a^{2008}+b^{2008}}=2010\)
Bài 1:
Viét: \(\left\{{}\begin{matrix}x_1+x_2=a\\x_1x_2=a-1\end{matrix}\right.\)
\(M=\dfrac{2x_1^2+x_1x_2+2x_2^2}{x_1^2x_2+x_1x_2^2}=\dfrac{2\left(x_1+x_2\right)^2-3x_1x_2}{x_1x_2\left(x_1+x_2\right)}=\dfrac{2a^2-3a+3}{a^2-a}\)
\(M=2^{2010}-\left(2^{2009}+2^{2008}+...+2^1+2^0\right)\)
Đặt \(A=2^{2009}+2^{2008}+...+2+2^0\)
\(=1+2+...+2^{2008}+2^{2009}\)
\(\Rightarrow2A=2+2^2+...+2^{2010}\)
\(\Rightarrow2A-A=\left(2+2^2+...+2^{2010}\right)-\left(1+2+...+2^{2009}\right)\)
\(\Rightarrow A=2^{2010}-1\)
\(\Rightarrow M=2^{2010}-\left(2^{2010}-1\right)\)
\(=2^{2010}-2^{2010}+1=1\)
Vậy M = 1
\(M=2^{2010}-\left(2^{2009}+2^{2008}+...+2^1+2^0\right)\)
\(M=2^{2010}-\left(2^{2009}+2^{2008}+...+2^1+2^0\right)\)
\(M=2^{2010}-2^{2009}-2^{2008}-...-2^1-2^0\)
\(M=2^{2009}\left(2-1\right)-2^{2008}-...-2^1-2^0\)
\(M=2^{2009}-2^{2008}-2^{2007}-...-2^1-2^0\)
\(M=2^{2008}\left(2-1\right)-2^{2007}-...-2^1-2^0\)
\(M=2^{2008}-2^{2007}-2^{2006}-...-2^1-2^0\)
...........................................
\(M=2^1-2^0=2-1=1\)
đặt M1 = 22009 + 22008 +...+21 + 20
⇒ 2M1 = 22010 + 22009 + ... + 22 + 21
⇒ 2M1 - M1 = 22010 + 22009 + ... + 22 + 21 - (22009 + 22008 + ... + 21 + 20)
⇒ M1 = 22010 - 20
⇒ M = 22010 - (22010 - 20)
⇒ M = 22010 - 22010 +20
⇒ M = 0 + 1 = 1
Vậy M = 1
Tính M=\(2^{2010}-(2^{2009}+2^{2008}+...+2^1+2^0)\)
\(M=2^{2010}-\left(2^{2009}+2^{2008}+...+2^1+2^0\right)\)
Gọi \(N=2^{2009}+2^{2008}+...+2^1+2^0\)
\(2N=2^{2010}+2^{2009}+...+2^2+2^1\\ 2N-N=\left(2^{2010}+2^{2009}+...+2^2+2^1\right)-\left(2^{2009}+2^{2008}+...+2^1+2^0\right)\\ N=2^{2010}-2^0\\ N=2^{2010}-1\)
Thay vào ta được
\(M=2^{2010}-\left(2^{2010}-1\right)\\ M=2^{2010}-2^{2010}+1\\ M=1\)
Vậy \(M=1\)
Ta có :
\(M=2^{2010}-\left(2^{2009}+2^{2008}+...+2^0\right)\)
Đặt A=22009+22008+..+20
\(A=2^{2009}+2^{2008}+...+2^0\\ 2A=2^{2010}+2^{2009}+...+2^1\\ \Rightarrow2A-A=A=2^{2010}-2^0\\ \Rightarrow M=2^{2010}-\left(2^{2010}-2^0\right)\\ M=2^{2010}-2^{2010}+1\\ \Rightarrow M=1\)
Chúc bạn học tốt!