Tim x biet
\(\left(2x-1\right)^2-2=30\)
Tim x biet : \(\left(x-3\right)^2=\left(2x-1\right)^2\)
(x - 3)2 = (2x - 1)2
=> |x - 3| = |2x - 1|
=> x - 3 = 2x-1 hoặc x - 3 = -(2x - 1)
x - 2x = -1 + 3 hoặc x - 3 = -2x + 1
-x = 2 hoặc x + 2x = 1 + 3
x = -2 hoặc 3x = 4
x = -2 hoặc x = 4 : 3
x = -2 hoặc x = 1,(3)
tim x biet
\(3x\left(x-1\right)-x\left(3x-2\right)=5\)
\(8x\left(2x+1\right)-4x\left(2x-3\right)=-40\)
\(\left(2x-1\right)\left(3x-1\right)-\left(3x-2\right)\left(2x-1\right)=3\)
a ) \(3x\left(x-1\right)-x\left(3x-2\right)=5\)
\(\Leftrightarrow3x^2-3x-3x^2+2x=5\)
\(\Leftrightarrow-x=5\)
\(\Leftrightarrow x=-5\)
Vậy phương trình có nghiệm x = - 5 .
a, \(3x\left(x-1\right)-x\left(3x-2\right)=5\)
\(\Rightarrow3x^2-3x-\left(3x^2-2x\right)=5\)
\(\Rightarrow3x^2-3x-3x^2+2x=5\)
\(\Rightarrow5x=5\Rightarrow x=1\)
Câu b,c làm tương tự! Cứ tách ra là làm được à!
b ) \(8x\left(2x+1\right)-4x\left(2x-3\right)=-40\)
\(\Leftrightarrow16x^2+8x-8x^2+12x=-40\)
\(\Leftrightarrow20x=-40\)
\(\Leftrightarrow x=-2\)
Vậy phương trình có nghiệm x = - 2
Tim m de pt \(x^2-2x-2\left|x-m\right|+1=0\) co 3 nghiem phan biet
Tim x biet
a/ \(20\left(\frac{x-2}{x+1}\right)^2-5\left(\frac{x+2}{x-1}\right)^2+48\left(\frac{x^2-4}{x^2-1}\right)=0\)
b/ \(\left(2x-1\right)^{2012}=\left(2x-1\right)^{2010}\)
\(b)\) \(\left(2x-1\right)^{2012}=\left(2x-1\right)^{2010}\)
\(\Leftrightarrow\)\(\left(2x-1\right)^{2010}.\left(2x-1\right)^2=\left(2x-1\right)^{2010}\)
\(\Leftrightarrow\)\(\left(2x-1\right)^2=1\)
\(\Leftrightarrow\)\(\orbr{\begin{cases}2x-1=1\\2x-1=-1\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=2\\2x=0\end{cases}}}\)
\(\Leftrightarrow\)\(\orbr{\begin{cases}x=\frac{2}{2}\\x=\frac{0}{2}\end{cases}\Leftrightarrow\orbr{\begin{cases}x=1\\x=0\end{cases}}}\)
Vậy \(x=0\) hoặc \(x=1\)
Chúc bạn học tốt ~
3, tim x, biet ;
a,\(3x\left[12x-4\right]-9x\left[4x-3\right]=30\)
b,\(x\left[5-2x\right]+2x\left[x-1\right]=15\)
a) \(36x^2-12x-36x^2+27x=30\)
\(15x=30\)
\(x=2\)
b) \(5x-2x^2+2x^2-2x=15\)
\(3x=15\)
\(x=5\)
tim x biet
\(2\frac{1}{3}-\frac{1}{6}\left|-2x+\frac{1}{2}\right|\)\(=\frac{1}{2}\left|-x+\frac{1}{2}\right|-\frac{2}{3}\)
Tim x,biet;
a/ \(\left(x-1\right)^2=0\)
b/ \(\left(x-2\right)^2-1=0\)
c/\(\left(2x-1\right)^3=-8\)
d/ \(\left(x+2\right)^2+1=0\)
a) \(\left(x-1\right)^2=0\Leftrightarrow x-1=0\Leftrightarrow x=1\) vậy \(x=1\)
b) \(\left(x-2\right)^2-1=0\Leftrightarrow\left(x-2\right)^2=1\) \(\Leftrightarrow\left\{{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=3\\x=1\end{matrix}\right.\) vậy \(x=3;x=1\)
c) \(\left(2x-1\right)^3=-8\Leftrightarrow2x-1=\sqrt[3]{-8}\Leftrightarrow2x-1=-2\)
\(\Leftrightarrow2x=-1\Leftrightarrow x=\dfrac{-1}{2}\) vậy \(x=\dfrac{-1}{2}\)
d) \(\left(x+2\right)^2+1=0\Leftrightarrow\left(x+2\right)^2=-1\) (vô lí)
vậy phương trình vô nghiệm
a) (x-1)2 = 0
<=> x-1 = 0
<=> x = 1
b) (x-2)2 - 1 = 0
<=> (x-2)2 = 1
<=> \(\left\{{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
<=> \(\left\{{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
c) (2x-1)3 = -8
<=> (2x-1)3 = -23
<=> 2x - 1 = -2
<=> 2x = -1
<=> x = \(-\dfrac{1}{2}\)
d) (x+2)2 + 1 = 0
<=> (x+2)2 = -1
<=> x+2 = -1
<=> x = -3
a, \(\left(x-1\right)^2=0\)
\(\Leftrightarrow\left(x-1\right)^2=0^2\)
\(\Leftrightarrow x-1=0\)
\(\Leftrightarrow x=1\)
Vậy ......
b, \(\left(x-2\right)^2-1=0\)
\(\Leftrightarrow\left(x-2\right)^2=1\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(x-2\right)^2=1^2\\\left(x-2\right)^2=\left(-1\right)^2\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=1\\x-2=-1\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\)
Vậy .....
c, \(\left(2x-1\right)^3=-8\)
\(\Leftrightarrow\left(2x-1\right)^3=\left(-2\right)^3\)
\(\Leftrightarrow2x-1=-2\)
\(\Leftrightarrow2x=-3\)
\(\Leftrightarrow x=-\dfrac{3}{2}\)
Vậy ...
d, \(\left(x+2\right)^2+1=0\)
\(\Leftrightarrow\left(x+2\right)^2=-1\)
\(\Leftrightarrow\) ko tìm dc giá trị của x thỏa mãn (do \(\left(x+2\right)^2\ge0\))
Cho da thuc \(f\left(x\right)=x^3+2x^2+ax+1\)
TIm a biet no \(f\left(x\right)=-2\)
Khi \(f\left(x\right)=-2\)
Ta có : \(f\left(-2\right)=\left(-2\right)^3+2.\left(-2\right)^2+a.\left(-2\right)+1\)
\(=-8+8+a.\left(-2\right)+1\)
\(=a.\left(-2\right)+1\)
kun ơi, nó là;
x3 + 2x2 +ax +1 = -2
bài này bn ấy cho thiếu x=? thì làm sao tính dc a? pk kun
Tim x,biet
\(\left(2x-1\right)^{2012}=\left(2x-1\right)^{2010}\)
\(\left(2x-1\right)^{2012}=\left(2x-1\right)^{2010}\)
\(\Leftrightarrow\left(2x-1\right)^{2012}-\left(2x-1\right)^{2010}=0\)
\(\Leftrightarrow[\left(2x-1\right)^{2010}.\left(2x-1\right)^2]-\left(2x-1\right)^{2010}=0\)\(\Leftrightarrow\left(2x-1\right)^{2010}.[\left(2x-1\right)^2-1]=0\)
\(\Leftrightarrow\left(2x-1\right)^{2010}.[\left(2x-1-1\right)\left(2x-1+1\right)]=0\)
\(\Leftrightarrow\left(2x-1\right)^{2010}.[\left(2x-2\right)2x]=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(2x-1\right)^{2010}\\2x\left(2x-2\right)=0\end{matrix}\right.=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1=0\\2x=0\\2x-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=0\\x=1\end{matrix}\right.\)
Vậy x \(\in\left\{\dfrac{1}{2};0;1\right\}\)
\((2x-1)^{2012} = (2x-1)^{2010} \)
\(\)\(\Leftrightarrow\)\((2x-1)^{2012} - (2x-1)^{2010} = 0\)
\(\Leftrightarrow\)\((2x-1)^{2010} . [(2x-1)^{2} - 1] = 0\)
\(\Leftrightarrow\)\((2x-1)^{2010} . (2x-2).2x = 0\)
\(\Leftrightarrow\)\(4 . (2x-1)^{2010} . (x-1) . x = 0\)
\(\Rightarrow\)\(\left[{}\begin{matrix}\left(2x-1\right)^{2010}=0\\x-1=0\\x=0\end{matrix}\right.\)
\(\Rightarrow\)\(\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=1\\x=0\end{matrix}\right.\)
\(Vậy \) \(x= \)\(\dfrac{1}{2}\); \(x=1\) \(hay\) \(x=0\)