(3x-7)^2012 - (3x - 7)^2014 = 0. Tìm x
(3x-7)2012-(3x-7)2014=A. Tìm A?
Tìm x :
6x(1-3x)+9x(2x-7)+171=0
tập hợp x:x+1/2015+x+2/2014=x+3/2013+x+4/2012
\(6x\left(1-3x\right)+9x\left(2x-7\right)+171=0\)
\(\Leftrightarrow6x-18x^2+18x^2-63x+171=0\)
\(\Leftrightarrow-57x=-171\)
\(\Leftrightarrow x=3\)
\(\frac{x+1}{2015}+\frac{x+2}{2014}=\frac{x+3}{2013}+\frac{x+4}{2012}\)
\(\Leftrightarrow\left(\frac{x+1}{2015}+1\right)+\left(\frac{x+2}{2014}+1\right)-\left(\frac{x+3}{2013}+1\right)-\left(\frac{x+4}{2012}+1\right)=0\)
\(\Leftrightarrow\)\(\frac{x+2016}{2015}+\frac{x+2016}{2014}-\frac{x+2016}{2013}+\frac{x+2016}{2012}=0\)
\(\Leftrightarrow\left(x+2016\right)\left(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{2013}-\frac{1}{2012}\right)=0\)
\(\Leftrightarrow x+2016=0\) ( vì \(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{2013}-\frac{1}{2012}\ne0\) )
\(\Leftrightarrow x=-2016\)
Câu 1: Tìm x, y, z biết:
(3x-5)^2010+(y-1)^2012+(x-z)^2014=0
Câu 2: tìm x, y thuộc N biết:
116-y^2=7(x-2013)^2
3x-72012=3x-72014
3x-7^2012=3x-7^2014
suy ra:3x-3x=-7^2014+7^2012
suy ra 7^2012-7^2014=0(vô lí)
nên ko có x thỏa mãn
Tìm x:
a) 32x+22x+1=324
b) (3x-7)2012=(3x-7)2014
Trình bày giúp ạ
a) 32x + 32x+1 = 324
32x . 1 + 32x . 3 = 324
32x . ( 1 + 3 ) = 324
32x . 4 = 324
32x = 324 : 4
32x = 81
32x = 34
=> 2x = 4
=> x = 4 : 2 = 2
( 3x - 7 )2012 = ( 3x - 7 )2014
( 3x - 7 )2014 - ( 3x - 7 )2012 = 0
( 3x - 7 )2012 . [ ( 3x - 7 )2 - 1 ] = 0
\(\Rightarrow\orbr{\begin{cases}\left(3x-7\right)^{2012}=0\\\left(3x-7\right)^2-1=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}3x-7=0\\\left(3x-7\right)^2=1\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}3x=7\\3x-7=1\text{ hoặc }3x-7=-1\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{7}{3}\\3x=8\text{ hoặc }3x=6\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{7}{3}\\x=\frac{8}{3}\text{ hoặc }x=2\end{cases}}\)
(3x-7)^2012=(3x-7)^2014
Giúp mìh với!!!
( 3x - 7 ) ^ 2012 = ( 3x - 7 ) ^ 20147 = 0
( 3x - 7 ) ^ 2014 - ( 3x - 7 ) ^ 2012 = 0
( 3 x - 7 ) ^ 2012 . [ ( 3x - 7 ) ^ 2 - 1 ) = 0
=> ( 3x - 7 ) ^ 2012 = 0 hoặc ( 3x - 7 ) ^ 2 - 1 = 0
3 x - 7 = 0 ( 3x - 7 ) ^ 2 = 1
3x = 7 => 3x - 7 = 1 hoặc 3x - 7 = -1
x = 7 / 3 x = 8 / 3 x = 2
Vậy x = 7 / 3 hoặc x = 8 / 3 hoặc x = 2
(3x-7)^2012=(3x-7)^2014
<=> (3x-7)^2014 - (3x-7)^2012 = 0
<=> (3x-7)^2012.(3x-7)^2 - (3x-7)^2012 = 0
<=> (3x-7)^2012.[(3x-7)^2 - 1] = 0
=> (3x-7)^2012=0 hoặc (3x-7)^2-1=0
<=> 3x-7=0 hoặc (3x-7)^2=1
<=>x=7/3 hoặc 3x-7=-1;1
<=>x=7/3 hoặc x=2;8/3
Vậy .............
1. Tìm x, y, z biết:
( 3x- 5)2010 + ( y- 1)2012 +( x- z)2014= 0
2. Tìm x, y thuộc N
16- y2= 7( x- 2013)2
Shbh=a x h= 48 x (48 x \(\frac{1}{3}\) ) =768 (cm2 )
1. \(\left(3x-5\right)^{2010}+\left(y-1\right)^{2012}+\left(x-z\right)^{2014}=0\)
Vì \(\left(3x-5\right)^{2010}\ge0\forall x\); \(\left(y-1\right)^{2012}\ge0\forall y\); \(\left(x-z\right)^{2014}\ge0\forall x,z\)
\(\Rightarrow\left(3x-5\right)^{2010}+\left(y-1\right)^{2012}+\left(x-z\right)^{2014}\ge0\)
Dấu " = " xảy ra \(\Leftrightarrow\hept{\begin{cases}3x-5=0\\y-1=0\\x-z=0\end{cases}}\Leftrightarrow\hept{\begin{cases}3x=5\\y=1\\x=z\end{cases}}\Leftrightarrow\hept{\begin{cases}x=\frac{5}{3}\\y=1\\z=\frac{5}{3}\end{cases}}\)
Vậy \(x=z=\frac{5}{3}\)và \(y=1\)
Bài 1:
a) tìm x: \(\left(3x-7\right)^{2012}=\left(3x-7\right)^{2014}\)
b) So sánh \(2^{30}+3^{30}+4^{30}\)và \(3\times24^{10}\)
Tìm x,y,z
(3x-5)2010+(y-1)2012+(x-z)2014=0
Ta có \(\left(3x-5\right)^{2010}+\left(y-1\right)^{2012}+\left(x-z\right)^{2014}=0\left(1\right)\)
Vì \(2010;2012;2014\) đều là số mủ chẵn (2)
Từ (1) và (2)
\(\Rightarrow\left(3x-5\right)=0;\left(y-1\right)=0;\left(x-z\right)=0\)
\(\left(+\right)3x-5=0\Rightarrow3x=5\Rightarrow x=\frac{5}{3}\)
\(\left(+\right)y-1=0\Rightarrow y=1\)
\(\left(+\right)x-z=0\Rightarrow z=x=\frac{5}{3}\)
Vậy \(x=z=\frac{5}{3};y=1\)