5A. Tìm x, biết:
a) 8x(x - 2017) - 2x + 4034 = 0; b)
x + x2
2 8
= 0;
c) 4 - x = 2( x -4)2; d) (x2 + 1)(x - 2) + 2x = 4.
5B. Tìm x, biết:
a) x4 -16x2 =0; c) x8 + 36x4 =0;
b) (x - 5)3 - x + 5 = 0; d) 5(x - 2 ) - x2 + 4 = 0.
Tìm x, biết:
a) 8x(x - 2017) - 2x + 4034 = 0; b) x 2 + x 2 8 = 0;
c) 4 - x = 2 ( x - 4 ) 2 ; d) ( x 2 + 1)(x - 2) + 2x = 4.
Bài 1: Tìm x biết:
a) 8x.(x-2007)-2x+4034=0
b) x/2 + x2/8=0
c) 4-x= 2.(x-4)2
d) ( x2+1).(x-2)+2x=4
Mình đang cần gấp bài này, các bạn giúp mình nhé
a. \(8x\left(x-2007\right)-2x+4034=0\)
\(\Rightarrow\left(x-2017\right)\left(4x-1\right)\)
\(\Rightarrow\left[{}\begin{matrix}x-2017=0\\4x-1=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2017\\4x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2017\\x=\dfrac{1}{4}\end{matrix}\right.\)
Vậy x=2017 hoặc x=1/4
b.\(\dfrac{x}{2}+\dfrac{x^2}{8}=0\)
\(\Rightarrow\dfrac{x}{2}\left(1+\dfrac{x}{4}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{x}{2}=0\\1+\dfrac{x}{4}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\\dfrac{x}{4}=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-4\end{matrix}\right.\)
Vậy x=0 hoặc x=-4
c.\(4-x=2\left(x-4\right)^2\)
\(\Rightarrow\left(4-x\right)-2\left(x-4\right)^2=0\)
\(\Rightarrow\left(4-x\right)\left(2x-7\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}4-x=0\\2x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=\dfrac{7}{2}\end{matrix}\right.\)
Vậy x=4 hoặc x=7/2
d.\(\left(x^2+1\right)\left(x-2\right)+2x=4\)
\(\Rightarrow\left(x-2\right)\left(x^2+3\right)=0\)
Nxet: (x2+3)>0 với mọi x
=> x-2=0 <=>x=2
Vậy x=2
a, 8\(x\).(\(x-2007\)) - 2\(x\) + 4034 = 0
4\(x\)(\(x\) - 2007) - \(x\) + 2017 = 0
4\(x^2\) - 8028\(x\) - \(x\) + 2017 = 0
4\(x^2\) - 8029\(x\) + 2017 = 0
4(\(x^2\) - 2. \(\dfrac{8029}{8}\) \(x\) +( \(\dfrac{8029}{8}\))2) - (\(\dfrac{8029}{4}\))2 + 2017 = 0
4.(\(x\) + \(\dfrac{8029}{8}\))2 = (\(\dfrac{8029}{4}\))2 - 2017
\(\left[{}\begin{matrix}x=-\dfrac{8029}{8}+\dfrac{1}{2}.\sqrt{\left(\dfrac{8029}{4}\right)^2-2017}\\x=-\dfrac{8029}{8}-\dfrac{1}{2}.\sqrt{\left(\dfrac{8029}{4}\right)^2-2017}\end{matrix}\right.\)
Tìm x, biết :
a, 8x ( x- 2017) - 2x + 4034 = 0
b, x/2 + x^2/8 = 0
c, 4 - x = 2(x-4)^2
d, ( x^2 + 1) ( x-2) + 2x = 4
Giúp mk vs ạ mk đang cần gấp
tìm x
a,8x(x-2017)-2x+4034
b,4-x=2(x-4)^2
c,(x^2+1)(x-2)+2x=4
a) Thiếu VP
b) 4 - x = 2( x - 4 )2
<=> 4 - x = 2( x2 - 8x + 16 )
<=> 4 - x = 2x2 - 16x + 32
<=> 2x2 - 16x + 32 - 4 + x = 0
<=> 2x2 - 15x + 28 = 0
<=> 2x2 - 8x - 7x + 28 = 0
<=> 2x( x - 4 ) - 7( x - 4 ) = 0
<=> ( x - 4 )( 2x - 7 ) = 0
<=> \(\orbr{\begin{cases}x-4=0\\2x-7=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=4\\x=\frac{7}{2}\end{cases}}\)
c) ( x2 + 1 )( x - 2 ) + 2x = 4
<=> x3 - 2x2 + 3x - 2 - 4 = 0
<=> x3 - 2x2 + 3x - 6 = 0
<=> x2( x - 2 ) + 3( x - 2 ) = 0
<=> ( x - 2 )( x2 + 3 ) = 0
<=> x = 2 ( vì x2 + 3 ≥ 3 > 0 ∀ x )
a, thiếu
b, \(4-x=2\left(x-4\right)^2\Leftrightarrow4-x=2\left(x^2-8x+16\right)\)
\(\Leftrightarrow4-x=2x^2-16x+32\Leftrightarrow2x^2-15x+28=0\)
\(\Leftrightarrow\left(x-4\right)\left(2x-7\right)=0\Leftrightarrow\orbr{\begin{cases}x=4\\x=\frac{7}{2}\end{cases}}\)
c, \(\left(x^2+1\right)\left(x-2\right)+2x=4\Leftrightarrow x^3-2x^2+3x-6=0\Leftrightarrow x_1=2;x_2=\sqrt{3}i\)
a) Ta có: \(8x\left(x-2017\right)-2x=4034\) (hẳn đề là ntn-.-)
\(\Leftrightarrow8x^2-16136x-2x-4034=0\)
\(\Leftrightarrow8x^2-16138x-4034=0\)
Bấm nghiệm ra: \(x_1=2017,499938\) ; \(x_2=-0,24993...\)
b) Ta có: \(4-x=2\left(x-4\right)^2\)
\(\Leftrightarrow2\left(x^2-4x+4\right)+x-4=0\)
\(\Leftrightarrow2x^2-7x+4=0\)
\(\Leftrightarrow\left(x^2-\frac{7}{2}x+\frac{49}{16}\right)-\frac{17}{16}=0\)
\(\Leftrightarrow\left(x-\frac{7}{4}\right)^2-\left(\frac{\sqrt{17}}{4}\right)^2=0\)
\(\Leftrightarrow\left(x-\frac{7+\sqrt{17}}{4}\right)\left(x-\frac{7-\sqrt{17}}{4}\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{7+\sqrt{17}}{4}\\x=\frac{7-\sqrt{17}}{4}\end{cases}}\)
c) \(\left(x^2+1\right)\left(x-2\right)+2x=4\)
\(\Leftrightarrow\left(x^2+1\right)\left(x-2\right)+2\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(x^2+3\right)=0\)
Mà \(x^2+3\ge3>0\)
=> \(x-2=0\Rightarrow x=2\)
1. Tính giá trị biểu thức a) M = t(10 - 4t) - t ² (2t-5) - 2t + 5 tại T = 5 / 2
b) N = x ²(y - 1) - 5x(1 - y) tại x = -20 và y = 1001
c) P = y ²(x ² + y -1) - mx ² - my + m tại x = 9 và y = -80
d) Q = x(x - y) ³ - y(x - y) ² + xy ² -x ²y tại x - y = 7 và xy = 9
2. Tìm x, biết :
a) 8x( x - 2017) - 2x + 4034 = 0
b) x / 2 + x ² / 8 = 0
c) 4 - x = 2(x - 4) ²
d) (x ² + 1)(x - 2) + 2x = 4
3. Tìm x, biết
a) x^4 - 16x ² = 0
b) x^8 + 36x^4 = 0
c) (x - 5) ³ - x + 5 = 0
d) 5(x - 2) - x ² + 4 = 0
a) x2(x - 5) + 5 - x = 0; b) 3x4 - 9x3 = -9x2 + 27x;
c) x2(x + 8) + x2 = -8x; d) (x + 3)(x2 -3x + 5) = x2 + 3x.
e) 3x(x - 1) + x - 1 = 0;
f) (x - 2)(x2 + 2x + 7) + 2(x2 - 4) - 5(x - 2) = 0;
g) (2x - 1)2 - 25 = 0;
h) x3 + 27 + (x + 3)(x - 9) = 0.
i)8x3 - 50x = 0; k) 2(x + 3)-x2 - 3x = 0;
m)6x2 - 15x - (2x - 5)(2x + 5) =
a: \(\Leftrightarrow\left(x-5\right)\left(x+1\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=-1\\x=1\end{matrix}\right.\)
d: \(\Leftrightarrow\left(x+3\right)\left(x^2-4x+5\right)=0\)
\(\Leftrightarrow x+3=0\)
hay x=-3
Tìm x, biết:
a) 3x(x - 1) + x - 1 = 0;
b) (x - 2)( x 2 + 2x + 7) + 2( x 2 - 4) - 5(x - 2) = 0;
c) ( 2 x - 1 ) 2 - 25 = 0;
d) x 3 + 27 + (x + 3)(x - 9) = 0.
a) x = 1; x = - 1 3 b) x = 2.
c) x = 3; x = -2. d) x = -3; x = 0; x = 2.
Tìm x biết:
a) x 6 + 2 x 3 +1 = 0; b) x(x - 5) = 4x - 20;
c) x 4 -2 x 2 =8-4 x 2 ; d) ( x 3 - x 2 ) - 4 x 2 + 8x-4 = 0.
a) x = -1. b) x = 4 hoặc x = 5.
c) x = ± 2 . d) x = 1 hoặc x = 2.
Tìm x,biết
a) ( x+2)×(x+3)-(x -2)×(x+5)=0
b) (2x+3)×(x-4)+(x-5)×(x-2)=(3x-5)×(x-4)
c) (8-5x)×(x+2)+4(x-2)×(x+1)+2(x-2)×(x+2)=0
d) (8x-3)×(3x+2)-(4x+7)×(x+4)=(2x+1)×(5x-1)-33