( 2x + 1)^ 5= ( 2x+ 1) ^ 2011
( 2x + 1) ^ 5=( 2x+1) ^ 2011
(2x+1)5=(2x+1)2011\(\Leftrightarrow\)(2x+1)5-(2x+1)2011=0
\(\Leftrightarrow\left(2x+1\right)^5\left(1-\left(2x+1\right)^{2006}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(2x+1\right)^5=0\\1-\left(2x+1\right)^{2006}=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+1=0\\\left(2x+1\right)^{2006}=1\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=-1\\2x+1=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=0\end{matrix}\right.\)
Tìm x bt 2x/ 1 × 3 + 2x/ 3 x 5 + 2x / 5 x 7 +...+2x/2011×2013
Tìm x biết ( 2x + 1 )5 = ( 2x + 1 )2011
Bài làm
( 2x + 1 ) 5 = ( 2x + 1 ) 2011
=> 0 = ( 2x + 1 )2011 : ( 2x + 1 )5
=> 0 = ( 2x + 1 )2006
=> 02006 = ( 2x + 1 )2006
=> 2x + 1 = 0
=> 2x = -1
=> x = \(-\frac{1}{2}\)
Vậy x =\(-\frac{1}{2}\)
# Học tốt #
a) 2x-1/11+2x-2/12+2x-3/13=2x+5/5+2x+6/4+2x+7/3
b) x-1/2016+x-2/2015+x-3/2014+x-4/2013+x-5/2012 -5=0
c) x+2017/2+x+2015/3+x+2013/4+x+2011/5+8=0
Tìm số tự nhiên x thỏa mãn:
a) 5/1.6 + 5/6.11 +...+ 5/(5x + 1).(5x + 6) = 2010/2011
b) 1/3.5 + 1/5.7 + 1/7.9 +...+ 1/(2x + 1).(2x + 3) = 15/93
a) x+2/x-2-1/x=2/x*(x-2)
b)2/2x-6+2/2x+2+2x/(x+1)*(3-x)=0
c) x+1/2017+x+2/2016=x+3/2015+x+4/2014
d) x-45/5+x-44/6+x-43/7+x-42/8=4
e) x-3/2011+x+2/2012=x-2012/2+x-2011/3
a) ĐKXĐ: \(x\notin\left\{0;2\right\}\)
Ta có: \(\dfrac{x+2}{x-2}-\dfrac{1}{x}=\dfrac{2}{x\left(x-2\right)}\)
\(\Leftrightarrow\dfrac{x\left(x+2\right)}{x\left(x-2\right)}-\dfrac{x-2}{x\left(x-2\right)}=\dfrac{2}{x\left(x-2\right)}\)
Suy ra: \(x^2+2x-x+2-2=0\)
\(\Leftrightarrow x^2+x=0\)
\(\Leftrightarrow x\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(loại\right)\\x=-1\left(nhận\right)\end{matrix}\right.\)
Vậy: S={-1}
Tìm số tự nhiên x thỏa mãn: 5/1.6 + 5/6.11 +...+ 5/(5x+1).(5x+6) =2010/2011. b) 1/3.5+1/5.7+.,.+ 1/(2x+1).(2x+3) =15/93.
1-1/6+1/6-1/11+....+1/(5x+1)-1/(5x+2)=2010/2011 <=>1-1/(5x+2)=2010/2011 <=>1/2011=1/(5x+2) <=>x=401
=2/3.5+2/5.7+2/7.9+........+2/(2x+1).(2x+3)=15/93.2
=1/3-1/5+1/5-1/7+.........+1/(2x+1)-1/(2x+3)=30/93
=1/3-1/(2x+3)=30/93
=1/(2x+3)=1/3-30/93
1/(2x+3)=31/93-30/93
1/(2x+3)=1/93
(2x+3).1=1.93
2x+3=93
2x=93-3
2x=90
x=90:2
x=45
tìm x biết: |2x|^2011 +|2x-1|^2010 =1
a) 2x-1/11+2x-2/12+2x-3/13=2x+5/5+2x+6/4+2x+7/3
b) x-1/2016+x-2/2015+x-3/2014+x-4/2013+x-5/2012 -5=0
c) x+2017/2+x+2015/3+x+2013/4+x+2011/5+8=0
giúp mình với mọi người làm ơn đi mình cần gấp lắm!!!!