2x + 15 = 4x - 3x + 8

2x - 4x + 3x = 8 - 15

x = -7

1) \(\Rightarrow10x-16-12x+15=12x-16+11\)

\(\Rightarrow14x=4\Rightarrow x=\dfrac{2}{7}\)

2) \(\Rightarrow4x^2+4x+1-4x^2+13x-3-15=0\)

\(\Rightarrow17x=17\Rightarrow x=1\)

3) \(\Rightarrow\left(3x-1\right)\left(2x-7+6x-5\right)=0\)

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

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

2: Ta có: \(\left(2x+1\right)^2-\left(4x-1\right)\left(x-3\right)-15=0\)

\(\Leftrightarrow4x^2+4x+1-4x^2+12x+x-3-15=0\)

\(\Leftrightarrow17x=17\)

hay x=1

a) 2x+8≤ 0 

⇔2x≤-8

⇔x≤-4

b) 4x-7 ≥ 2x -5

⇔2x-12 ≥ 0

⇔2x≥12

⇔x≥6

c) (2x-8)(15-3x)>0

TH1: 2x-8>0 ⇒x>4

        15-3x>0⇒x<5 

TH2:  2x-8<0 ⇒x<4

        15-3x<0⇒x>5 (vô lí)

vậy 4<x<5

1: Ta có: \(\left(x+3\right)^2-\left(x+2\right)\left(x-2\right)=4x+17\)

\(\Leftrightarrow x^2+6x+9-x^2+4-4x=17\)

\(\Leftrightarrow x=2\)

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

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

\(\Leftrightarrow6x=6\)

hay x=1

a) ( x + 2 )( 3 - 4x ) = x² + 4x + 4

<=> ( x + 2 )( 3 - 4x ) = ( x + 2 )²

<=> 3 - 4x = x + 2

<=> -4x - x = 2 - 3

<=> -5x = -1

<=> x = \(\frac{1}{5}\)

b) x(2x - 7) - 4x + 14 = 0

<=> x(2x - 7) = 4x - 14

<=> x(2x - 7) = 2(2x - 7)

<=> x = 2

c) 3x - 15 = 2x(x - 5)

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

<=> 3 = 2x

<=> x = \(\frac{3}{2}\)

d) (2x + 1)(3x - 2) = (5x - 8)(2x + 1)

<=> 3x - 2 = 5x - 8

<=> 3x - 5x = -8 + 2

<=> -2x = -6

<=> x = 3

  2x - (-15) = 4x - ( 3x -8 )

suy ra 2x + 15 = 4x -3x +8

suy ra 2x + 15 = x + 8

suy ra 2x - x = 8 -15

suy ra x = -7

Vậy x =-7

nha 

<=> 2x + 15 = 4x - 3x + 8

<=> 2x - 4x + 3x = 8 - 15

<=> x                 = -7

(x+2x+3x)-(8+15+27)=4x+68

     6x       -      50       =4x+68

     6x- 4x                   =68+50

         2x                      =118

            59    =x

\(x-8+2x-15+3x-27=4x+68\)

\(\Leftrightarrow6x-50=4x+68\)

\(\Leftrightarrow6x-4x=68+50\)

\(\Leftrightarrow2x=118\)

\(\Leftrightarrow x=59\)

x-8+2x-15+3x-27=4x+68

(x+2x+3x)-8-15-27=4x+68

6x-(8+15+27)=4x+68

6x-50=4x+68

6x=4x+68+50

6x-4x=68+50

2x=118

x=118:2

x=59

Vậy x=59.k cho mk nha

a, \(4\left(18-5x\right)-12\left(3x-7\right)=15\left(2x-16\right)-6\left(x+14\right)\)

\(\Rightarrow72-20x-36x+84=30x-240-6x-84\)

\(\Rightarrow-20x-36x-30x+6x=-240-84-72-84\)

\(\Rightarrow-80x=-480\Rightarrow x=6\)

b, \(5\left(3x+5\right)-4\left(2x-3\right)=5x+3\left(2x+12\right)+1\)

\(\Rightarrow15x+25-8x+12=5x+6x+36+1\)

\(\Rightarrow15x-8x-5x-6x=36+1-25-12\)

\(\Rightarrow-4x=0\Rightarrow x=0\)

c, \(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)

\(\Rightarrow10x-16-12x+15=12x-16+11\)

\(\Rightarrow10x-12x-12x=-16+11+16-15\)

\(\Rightarrow-14x=-4\Rightarrow x=\dfrac{2}{7}\)

d, \(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}=182\)

\(\Rightarrow5x-3\left[4x-2\left(4x-15x+6\right)\right]=182\)

\(\Rightarrow5x-3\left(4x-8x+30x-12\right)=182\)

\(\Rightarrow5x-12x+24x-90x+36=182\)

\(\Rightarrow-73x=182-36\)

\(\Rightarrow-73x=146\Rightarrow x=-2\)

Chúc bạn học tốt!!!