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19 tháng 12 2016

x ( 2x - 3 ) + 2 = 2x2 - 10

=> 2x2 - 3x + 2 = 2x2 - 10

=> -3x + 2 = -10

=> -3x = -12

=> x = 4

Vậy x = 4

12 tháng 8 2023

\(\left(x-3\right)=\left(3-x\right)^2\)

\(\Leftrightarrow x-3=\left(x-3\right)^2\)

\(\Leftrightarrow\left(x-3\right)-\left(x-3\right)^2=0\)

\(\Leftrightarrow\left(x-3\right)\left[1-\left(x-3\right)\right]=0\)

\(\Leftrightarrow\left(x-3\right)\left(4-x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\4-x=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)

___________

\(x^3+\dfrac{3}{2}x^2+\dfrac{3}{4}x+\dfrac{1}{8}=\dfrac{1}{64}\)

\(\Leftrightarrow x^3+3\cdot\dfrac{1}{2}\cdot x^2+3\cdot\left(\dfrac{1}{2}\right)^2\cdot x+\left(\dfrac{1}{2}\right)^3=\dfrac{1}{64}\)

\(\Leftrightarrow\left(x+\dfrac{1}{2}\right)^3=\left(\dfrac{1}{4}\right)^3\)

\(\Leftrightarrow x+\dfrac{1}{2}=\dfrac{1}{4}\)

\(\Leftrightarrow x=\dfrac{1}{4}-\dfrac{1}{2}\)

\(\Leftrightarrow x=-\dfrac{1}{4}\)

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14 tháng 1 2022

\(2x\left(x-5-x\right)=10\\ 2x.\left(-5\right)=10\\ 2x=-2\\ x=\dfrac{-2}{2}=-1\)

11 tháng 10 2021

\(a,\Rightarrow x^2\left(5x-2\right)-\left(5x-2\right)=0\\ \Rightarrow\left(x-1\right)\left(x+1\right)\left(5x-2\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=1\\x=-1\\x=\dfrac{2}{5}\end{matrix}\right.\\ b,\Rightarrow2x\left(3x-5\right)+6x-10=0\\ \Rightarrow2x\left(3x-5\right)+2\left(3x-5\right)=0\\ \Rightarrow\left(2x+2\right)\left(3x-5\right)=0\\ \Rightarrow2\left(x+1\right)\left(3x-5\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{5}{3}\end{matrix}\right.\)

1 tháng 11 2021

1.

a) \(2x^4-4x^3+2x^2\)

\(=2x^2\left(x^2-2x+1\right)\)

\(=2x^2\left(x-1\right)^2\)

b) \(2x^2-2xy+5x-5y\)

\(=\left(2x^2-2xy\right)+\left(5x-5y\right)\)

\(=2x\left(x-y\right)+5\left(x-y\right)\)

\(=\left(x-y\right)\cdot\left(2x+5\right)\)

1 tháng 11 2021

2 . 

a,

\(4x\left(x-3\right)-x+3=0\)

\(4x\left(x-3\right)-\left(x-3\right)=0\)

\(\left(x-3\right)\left(4x-1\right)=0\)

\(\left[{}\begin{matrix}x-3=0\\4x-1=0\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=3\\4x=1\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=3\\x=\dfrac{1}{4}\end{matrix}\right.\)

vậy \(x\in\left\{3;\dfrac{1}{4}\right\}\)

b, 

\(\)\(\left(2x-3\right)^2-\left(x+1\right)^2=0\)

\(\left(2x-3-x-1\right)\left(2x-3+x+1\right)\) = 0

\(\left(x-4\right)\left(3x-2\right)=0\)

\(\left[{}\begin{matrix}x-4=0\\3x-2=0\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=4\\3x=2\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=4\\x=\dfrac{2}{3}\end{matrix}\right.\)

vậy \(x\in\left\{4;\dfrac{2}{3}\right\}\)

15 tháng 9 2021

a. (2x + 1)2 - 4x2 + 2x2 - 2 = 0

<=> (2x + 1 - 2x)(2x + 1 + 2x) + 2(x2 - 1) = 0

<=> (4x + 1) + 2x2 - 2 = 0

<=> 4x + 1 + 2x2 - 2 = 0

<=> 2x2 + 4x - 2 + 1 = 0

<=> 2x2 + 4x - 1 = 0

<=> 2x2 + 4x = 1

<=> 2x(x + 2) = 1

Vì 1 chỉ có tích là 1 . 1 nên:

<=> \(\left[{}\begin{matrix}2x=1\\x+2=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=-1\end{matrix}\right.\)

15 tháng 9 2021

\(a,\Leftrightarrow4x^2+4x+1-4x^2+2x^2-2=0\\ \Leftrightarrow2x^2+4x-1=0\\ \Leftrightarrow2\left(x^2+2x+1\right)-3=0\\ \Leftrightarrow2\left(x+1\right)^2-3=0\\ \Leftrightarrow\left(x+1\right)^2=\dfrac{3}{2}\\ \Leftrightarrow\left[{}\begin{matrix}x+1=\sqrt{\dfrac{3}{2}}\\x+1=-\sqrt{\dfrac{3}{2}}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-2-\sqrt{6}}{2}\\x=\dfrac{-2+\sqrt{6}}{2}\end{matrix}\right.\)

\(b,\left(x-2\right)\left(x+2\right)-\left(x+3\right)^2-2x-5=0\\ \Leftrightarrow x^2-4-x^2-6x-9-2x-5=0\\ \Leftrightarrow-8x=18\\ \Leftrightarrow x=-\dfrac{9}{4}\)

20 tháng 12 2019

a) x = 2 7                         b) x = 2.

c) x = 2                          d) x = 1.

31 tháng 8 2021

a) 2x2 - 3x - 2 = 0.

<=> (2x + 1)(x - 2) = 0

<=> 2x + 1 = 0 hoặc x - 2 = 0

<=> x = -1/2 hoặc x = 2

31 tháng 8 2021

b) 3x2 - 7x - 10 = 0.

<=> (x + 1)(3x - 10) = 0

<=> x = -1 hoặc x = 10/3