a) 4x(x-1) = x-1 

   4x(x-1) - ( x-1) = 0

(4x - 1) (x-1 ) = 0

=>  4x -1=0                                x-1=0

       x=1/4                                     x=1

b) 2x³ -50x =0

  2x( x² - 25 ) = 0

=>  2x = 0                                                       x² -25 = 0

        x=0                                                         x² =25   => x =-5

                                                                                           x=5

c) 5x(2x-7)-14x = -49

5x(2x-7) -(14x -49 ) =0

5x(2x-7) - 7(2x-7) = 0

(5x-7)(2x-7)=0

=>  5x-7 =0                                                2x-7=0

     x=7/5                                                       x=7/2

Vậy .....

hok tốt

. Ai đó giúp tôi đi mà ._.

bài khó quá bạn ạ

a,2x^2=x 

=>2x^2 -x=0

=>x(2x-1)=0

th1 x=0

th2 2x-1=0 => 2x=1 =>x=1/2

b,x^2-1/36=0

<=> x^2-(1/6)^2=0

<=> (x-1/6)(x+1/6)=0

th1 x-1/6=0 =>x=1/6

th2 x+1/6=0 =>x=-1/6

e) \(x\left(x-2\right)-5x+10=0\)

\(\Leftrightarrow x\left(x-2\right)-5\left(x-2\right)=0\)

\(\Leftrightarrow\left(x-5\right)\left(x-2\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\x-2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=5\\x=2\end{cases}}\)

Vậy x = 2 hoặc x = 5

g) \(x^3-x=0\)

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

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x^2-1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}\)

Vậy \(x\in\left\{0;\pm1\right\}\)

a) 4x²  - 2x + 3 - 4x.(x - 5) = 7x - 3

--> 4x² - 2x + 3 - 4x² + 20x = 7x - 3

--> 4x² - 2x - 4x² + 20x - 7x = -3 - 3

--> 11x = -6

--> x = \(\frac{-6}{11}\)

b) -3x.(x - 5) + 5.(x - 1) + 3x² = 4x

--> -3x² + 15x + 5x - 5 + 3x² = 4x

--> -3x²  + 15x + 5x + 3x² - 4x = 5 

--> 16x = 5

--> x = \(\frac{5}{16}\)

c) 7x.(x - 2) - 5.(x - 1) = 21x² - 14x² + 3

--> 7x² - 14x - 5x + 5 = 7x² + 3 

--> 7x²  - 14x - 5x - 7x²  = -5 + 3 

--> -19x = -2 

--> x = \(\frac{2}{19}\)

d) 3.(5x - 1) - x.(x - 2) + x² - 13x = 7

--> 15x - 3 - x² + 2x + x² - 13x = 7

--> 15x - x² + 2x + x² - 13x = 3 + 7

--> 4x = 10

--> x = \(\frac{5}{2}\)

e) \(\frac{1}{5}\)x.(10x - 15) - 2x.(x - 5) = 12

--> 2x² - 3x - 2x² + 10x = 12

--> 7x = 12

--> x = \(\frac{12}{7}\)

~ Học tốt ~

a) 4x² - 2x + 3 - 4x(x - 5) = 7x - 3

=> 4x² - 2x + 3 - 4x² + 20x = 7x - 3

=> 18x + 3 = 7x - 3

=> 18x - 7x = -3 - 3

=> 11x = -6

=>  x = -6/11

b) -3x(x - 5) + 5(x - 1) + 3x² = 4x

=> -3x² + 15x + 5x - 5 + 3x² = 4x

=> 20x - 5 = 4x

=> 20x - 4x = 5

=> 16x = 5

=> x = 5/16

\(c,7x\left(x-2\right)-5\left(x-1\right)=21x^2-14x^2+3\)

\(\Leftrightarrow7x^2-14x-5x+5=7x^2+3\)

\(\Leftrightarrow7x^2-7x^2-19x=3-5\)

\(\Leftrightarrow-19x=-2\)

\(\Leftrightarrow x=\frac{2}{19}\)

a) 4x² - 2x + 3 - 4x.(x - 5) = 7x - 3

<=> 18x + 3 = 7x - 3

<=> 18x = 7x - 3 - 3

<=> 18x = 7x - 6

<=> 18x - 7x = -6

<=> 11x = -6

<=> x = -6/11

=> x = -6/11

b) -3x.(x - 5) + 5.(x - 1) + 3x² = 4x

<=> 20x - 5 = 4x

<=> 20x = 4x + 5

<=> 20x - 4x = 5

<=> 16x = 5

<=> x = 5/16

=> x = 5/16

c) 7x.(x - 2) - 5.(x - 1) = 21x² - 14x² + 3

<=> 7x.(x - 2) - 5.(x - 1) = 7x² + 3

<=> 7x² - 19x + 5 = 7x² + 3

<=> 7x² - 19x = 7x² + 3 - 5

<=> 7x² - 19x = 7x² - 2 

<=> 7x² - 19x - 7x² = -2

<=> -19x = -2

<=> x = 2/19

=> x = 2/19

d) 3.(5x - 1) - x.(x - 2) + x² - 13x = 7

<=> 4x - 3 = 7

<=> 4x = 7 + 3

<=> 4x = 10

<=> x = 10/4

=> x = 5/2

e) 1/5x.(10x - 15) - 2x.(x - 5) = 12

<=> x(2x - 3) - 2x(x - 5) = 12

<=> 7x = 12

<=> x = 12/7

=> x = 12/7

ko ai rảnh viết hết đâu bn

b, (x-2)(x+1)^2 + (x+1)(x-2)^2 = 0 

(x-2)(x+1)[(x+1)+(x-2)]=0 

(x-2)(x+1)(2x-1)=0 

Therefore, three possible answers for x: 

(2x-1) = 0, x = 1/2 

(x+1) = 0, x = -1 

(x-2) = 0, x = 2 

X = 2, -1 or 1/2 

a) \(-x^2+14x-49=0\)

\(\Leftrightarrow14^2-4.1.49\)

\(\Leftrightarrow14^2-196\)

\(\Leftrightarrow196-196\)

\(\Leftrightarrow x_{1;2}=\frac{-14\pm\sqrt{0}}{2.\left(-1\right)}\)

\(\Leftrightarrow x=\frac{-14}{-2}\)

\(\Rightarrow x=7\)

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

\(\Leftrightarrow4^2-4.4.1\)

\(\Leftrightarrow16-16\)

\(\Leftrightarrow x_{1;2}=\frac{-4\pm\sqrt{0}}{2.4}\)

\(\Leftrightarrow x=\frac{-4}{2.4}\)

\(\Rightarrow x=-\frac{1}{2}\)

c) \(\left(2x-4\right)\left(3x+1\right)+\left(x-2\right)^2=0\)

\(\Leftrightarrow7x^2-14x=0\)

\(\Rightarrow\orbr{\begin{cases}x=2\\x=0\end{cases}}\)

d) \(\left(x^2-5x+7\right)^2-\left(2x-5\right)^2=0\)

\(\Leftrightarrow\left(x-1\right)\left(x-2\right)\left(x-3\right)\left(x-4\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=1;2\\x=3;4\end{cases}}\)

P/s: Không chắc nha

\(2x^3-50x=0\)

<=>  \(2x\left(x^2-25\right)=0\)

<=>   \(2x\left(x-5\right)\left(x+5\right)=0\)

đến đây

bạn tự giải nhé

hk tốt