a, \(\left(3x-1\right)\left(2x+7\right)-\left(2x+1\right)\left(6x-5\right)=16\)

\(\Leftrightarrow6x^2+19x-7-12x^2+4x+5=16\)

\(\Leftrightarrow-6x^2+23x-18=0\Leftrightarrow\left(2x-9\right)\left(3x+2\right)=0\Leftrightarrow x=\frac{9}{2};x=-\frac{3}{2}\)

\(\Leftrightarrow6x+21x-2x-7-6x^2+5+6x+5=16\)

\(\Leftrightarrow6x+21x-2x-6x^2-6x=16+7-5-5\)

\(\Leftrightarrow13x=13\)

\(\Leftrightarrow x=1\)

\(a,\left(x-3\right)\left(x+7\right)-\left(x+5\right)\left(x-1\right)=0\)

\(x^2-3x+7x-21-x^2-5x+x+5=0\)

\(-16=0\)

vậy pt vô nghiệm

\(b,\left(3x-1\right)\left(2x+7\right)-\left(x+1\right)\left(6x-5\right)=16\)

\(6x^2-2x+21x-7-6x^2-6x+5x+5=16\)

\(18x=18\)

\(x=1\left(TM\right)\)

x = 1 tm

Trả lời:

a, ( x - 3 ) ( x + 7 ) - ( x + 5 ) ( x - 1 ) = 0

<=> x² + 7x - 3x - 21 - ( x² - x + 5x - 5 ) = 0

<=> x² + 7x - 3x - 21 - x² + x - 5x + 5 = 0

<=> - 16 = 0 ( vô lí )

Vậy pt vô nghiệm.

b, ( 3x - 1 ) ( 2x + 7 ) - ( x + 1 ) ( 6x - 5 ) = 16

<=> 6x² + 21x - 2x - 7 - ( 6x² - 5x + 6x - 5 ) = 16

<=>  6x² + 21x - 2x - 7 - 6x² + 5x - 6x + 5 = 16

<=> 18x - 2 = 16

<=> 18x = 18

<=> x = 1

Vậy x = 1 là nghiệm của pt.

a: =>2x^2-2x+2x-2-2x^2-x-4x-2=0

=>-5x-4=0

=>x=-4/5

b: =>6x^2-9x+2x-3-6x^2-12x=16

=>-19x=19

=>x=-1

c: =>48x^2-12x-20x+5+3x-48x^2-7+112x=81

=>83x=83

=>x=1

a.

\(\left(3x-1\right)\left(2x+7\right)-\left(x+1\right)\left(6x-5\right)=16\)

\(6x^2+21x-2x-7-6x^2+5x-6x+5=16\)

\(\left(6x^2-6x^2\right)+\left(21x-2x+5x-6x\right)-\left(7-5\right)=16\)

\(18x-2=16\)

\(18x=16+2\)

\(18x=18\)

\(x=\frac{18}{18}\)

\(x=1\)

b.

\(\left(10x+9\right)x-\left(5x-1\right)\left(2x+3\right)=8\)

\(10x^2+9x-10x^2-15x+2x+3=8\)

\(\left(10x^2-10x^2\right)-\left(15x-9x-2x\right)+3=8\)

\(-4x=8-3\)

\(-4x=5\)

\(x=-\frac{5}{4}\)

c.

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

\(21x-15x^2-35+25x+15x^2-10x+6x-4-2=0\)

\(\left(15x^2-15x^2\right)+\left(25x+21x-10x+6x\right)-\left(35+4+2\right)=0\)

\(42x=41\)

\(x=\frac{41}{42}\)

- mọi người ơi giúp mình với ạ. ai mình cx cho đúng

(3x-1)(2x+7)-(x+1)(6x-5)=16

=6x^2+21x-2x-7-(6x^2-5x+6x-5)=16

=6x^2+21x-2x-7-6x^2+5x-6x+5=16

=18x-2=16

18x=16+2

18x=18

x=1

​vậy x=1

bn đùa mk à 

(3x-1)(2x+7)-(x+1)(6x-5)=16

=6x^2+21x-2x-7-(6x^2-5x+6x-5)=16

=6x^2+21x-2x-7-6x^2+5x-6x+5=16

=18x-2=16

18x=16+2

18x=18

x=1

​vậy x=1

(3x-1)(2x+7)-(x+1)(6x-5)=16
<=> (6x^2+21x-2x-7)-(6x^2-5x+6x-5)=16
<=> 6x^2+21x-2x-7-6x^2+5x-6x+5=16

<=> (6x^2 -6x^2) + ( 21x-2x+5x-6x)-(7+5)=166x)-(7+5)=16
<=>18x-2=16
<=>18x=18

<=> x=1

Noob ơi, bạn phải đưa vào máy tính ý solve cái là ra x luôn, chỉ tội là đợi hơi lâu

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

=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84

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

=> 156 -  56x = 24x - 324 

=>  24x + 56x = 324 + 156 

=> 80x = 480 

=> x = 480 : 80 =  6 

Vậy x = 6 

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

=> 15x + 25 - 8x + 12 = 5x + 6x + 36 + 1 

=> (15x - 8x) + (25 + 12) = 11x + 37 

=> 7x + 37 = 11x + 37 

=> 11x - 7x = 0 

=>  x = 0