a/ \(\left(12x-5\right)\left(4x-1\right)+\left(3x-7\right)\left(1-16x\right)=81\)

<=> \(48x^2-12x-20x+5+3x-48x^2-7+112x=81\)

<=> \(83x-2=81\)

<=> \(83x=83\)

<=> \(x=1\)

b/ \(\left(2x-3\right)\left(2x+3\right)-\left(4x+1\right)x=1\)

<=> \(4x^2-9-4x^2-x=1\)

<=> \(-\left(9+x\right)=1\)

<=> \(9+x=-1\)

<=> \(x=-10\)

c/ \(3x^2-\left(x+2\right)\left(3x-1\right)=-7\)

<=> \(3x^2-\left(3x^2-x+6x-2\right)=-7\)

<=> \(3x^2-3x^2+x-6x+2=-7\)

<=> \(-5x+2=-7\)

<=> \(-5x=-9\)

<=> \(x=\frac{9}{5}\)

a: =>1/3:x=3/5-2/3=9/15-10/15=-1/15

=>x=-1/3:1/15=5

b: \(\Leftrightarrow x\cdot\dfrac{2}{3}-3=\dfrac{2}{5}\cdot\left(-10\right)=-4\)

=>x*2/3=-1

=>x=-3/2

c: =>2x+1=4 hoặc 2x+1=-4

=>x=3/2 hoặc x=-5/2

h: =>x-3=4

=>x=7

g: =>2x-1=3

=>2x=4

=>x=2

f: \(\Leftrightarrow x\cdot\left(\dfrac{3}{2}-\dfrac{7}{3}\right)=\dfrac{3}{2}-\dfrac{2}{3}\)

=>x*-5/6=5/6

=>x=-1

d: =>|2x-1|=3

=>2x-1=3 hoặc 2x-1=-3

=>x=-1 hoặc x=2

a,3x.(2x+3)-(2x+5).(3x-2)=8

x=1

b,5x(x+2)-x.(2x-7)-3x^2=81

x=81/17

~~~~~~~~~~~ai đi ngang qua nhớ để lại k ~~~~~~~~~~~~~

 ~~~~~~~~~~~~ Chúc bạn sớm kiếm được nhiều điểm hỏi đáp ~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~ Và chúc các bạn trả lời câu hỏi này kiếm được nhiều k hơn ~~~~~~~~~~~~

\(2x^2+3\left(x-1\right)\left(x+1\right)=5x\left(x+1\right)\)

=> \(2x^2+3\left(x^2-1\right)=5x^2+5x\)

=> \(2x^2+3x^2-3-5x^2-5x=0\)

=> \(-3-5x=0\)

=> \(5x=-3\Rightarrow x=-\frac{3}{5}\)

\(x\left(2x-1\right)\left(x+5\right)-\left(2x^2+1\right)\left(x+\frac{9}{2}\right)=\frac{7}{2}\)

=> \(x\left[2x\left(x+5\right)-1\left(x+5\right)\right]-2x^2\left(x+\frac{9}{2}\right)-1\left(x+\frac{9}{2}\right)=\frac{7}{2}\)

=> \(x\left(2x^2+10x-x-5\right)-2x^3-9x^2-x-\frac{9}{2}=\frac{7}{2}\)

=> \(2x^3+10x^2-x^2-5x-2x^3-9x^2-x-\frac{9}{2}=\frac{7}{2}\)

=> \(\left(2x^3-2x^3\right)+\left(10x^2-x^2-9x^2\right)+\left(-5x-x\right)-\frac{9}{2}=\frac{7}{2}\)

=> \(-6x-\frac{9}{2}=\frac{7}{2}\)

=> \(-6x=8\Rightarrow x=-\frac{8}{6}=-\frac{4}{3}\)

\(\left(12x-5\right)\left(4x-1\right)+\left(3x-7\right)\left(1-16x\right)=81\)

=> 12x(4x - 1) - 5(4x - 1) + 3x(1 - 16x) - 7(1 - 16x) = 81

=> 48x² - 12x - 20x + 5 + 3x - 48x² - 7 + 112x = 81

=> -12x - 20x + 3x + 112x + 5 - 7 = 81

=> 83x + 5 - 7 = 81

=> 83x = 81 + 7 - 5

=> 83x = 83

=> x = 1

1) \(2x^2+3\left(x-1\right)\left(x+1\right)=5x\left(x+1\right)\)

\(\Leftrightarrow2x^2+3x^2-3-5x^2-5x=0\)

\(\Leftrightarrow5x=-3\)

\(\Rightarrow x=-\frac{3}{5}\)

2) \(x\left(2x-1\right)\left(x+5\right)-\left(2x^2+1\right)\left(x+\frac{9}{2}\right)=\frac{7}{2}\)

\(\Leftrightarrow2x^3+9x^2-5x-2x^3-9x^2-x-\frac{9}{2}=\frac{7}{2}\)

\(\Leftrightarrow-6x=8\)

\(\Rightarrow x=-\frac{4}{3}\)

3) \(\left(12x-5\right)\left(4x-1\right)+\left(3x-7\right)\left(1-16x\right)=81\)

\(\Leftrightarrow48x^2-32x+5-48x^2+115x-7=81\)

\(\Leftrightarrow83x=83\)

\(\Rightarrow x=1\)

a) 2x² + 3( x - 1 )( x + 1 ) = 5x( x + 1 )

<=> 2x² + 3( x² - 1 ) = 5x² + 5x

<=> 2x² + 3x² - 5x² - 5x = 3

<=> -5x = 3

<=> x = -3/5

b) x( 2x - 1 )( x + 5 ) - ( 2x² + 1 )( x + 9/2 ) = 7/2

<=> x( 2x² + 9x - 5 ) - ( 2x³ + 9x² + x + 9/2 ) = 7/2

<=> 2x³ + 9x² - 5x - 2x³ - 9x² - x - 9/2 = 7/2

<=> -6x - 9/2 = 7/2

<=> -6x = 8

<=> x = -8/6 = -4/3

c) ( 12x - 5 )( 4x - 1 ) + ( 3x - 7 )( 1 - 16x ) = 81

<=> 48x² - 32x + 5 + 115x - 48x - 7 = 81

<=> 83x - 2 = 81

<=> 83x = 83

<=> x = 1

g: Ta có: \(3\left(2x-1\right)\left(3x-1\right)-\left(2x-3\right)\left(9x-1\right)=0\)

\(\Leftrightarrow3\left(6x^2-5x+1\right)-\left(18x^2-29x+3\right)=0\)

\(\Leftrightarrow18x^2-15x+3-18x^2+29x-3=0\)

\(\Leftrightarrow14x=0\)

hay x=0

w

* Trả lời:

\(\left(1\right)\) \(-3\left(1-2x\right)-4\left(1+3x\right)=-5x+5\)

\(\Leftrightarrow-3+6x-4-12x=-5x+5\)

\(\Leftrightarrow6x-12x+5x=3+4+5\)

\(\Leftrightarrow x=12\)

\(\left(2\right)\) \(3\left(2x-5\right)-6\left(1-4x\right)=-3x+7\)

\(\Leftrightarrow6x-15-6+24x=-3x+7\)

\(\Leftrightarrow6x+24x+3x=15+6+7\)

\(\Leftrightarrow33x=28\)

\(\Leftrightarrow x=\dfrac{28}{33}\)

\(\left(3\right)\) \(\left(1-3x\right)-2\left(3x-6\right)=-4x-5\)

\(\Leftrightarrow1-3x-6x+12=-4x-5\)

\(\Leftrightarrow-3x-6x+4x=-1-12-5\)

\(\Leftrightarrow-5x=-18\)

\(\Leftrightarrow x=\dfrac{18}{5}\)

\(\left(4\right)\) \(x\left(4x-3\right)-2x\left(2x-1\right)=5x-7\)

\(\Leftrightarrow4x^2-3x-4x^2+2x=5x-7\)

\(\Leftrightarrow-x-5x=-7\)

\(\Leftrightarrow-6x=-7\)

\(\Leftrightarrow x=\dfrac{7}{6}\)

\(\left(5\right)\) \(3x\left(2x-1\right)-6x\left(x+2\right)=-3x+4\)

\(\Leftrightarrow6x^2-3x-6x^2-12x=-3x+4\)

\(\Leftrightarrow-15x+3x=4\)

\(\Leftrightarrow-12x=4\)

\(\Leftrightarrow x=-\dfrac{1}{3}\)