`b,2(x+1)=5x-7`

`=>2x+2=5x-7`

`=>3x=9`

`=>x=3`

`c,3-4x(25-2x)=8x^2+x-300`

`<=>3-100x+8x^2=8x^2+x-300`

`<=>101x=303`

`<=>x=3`

`d,(10x+3)/12=1+(6+8x)/9`

`<=>(10x+3)/12=(8x+15)/9`

`<=>30x+9=32x+60`

`<=>2x=-51`

`<=>x=-51/2`

`a) 8x^2 - 8xy - 4x + 4y`

`= 8x ( x - y ) - 4 ( x - y )`

`= ( x - y ) ( 8x - 4 )`

__________________________

`b) x^3 + 10x^2 + 25x - xy^2`

`=x ( x^2 + 10x + 25 ) - xy^2`

`= x ( x + 5 )^2 - xy^2`

`= x [ ( x + 5 )^2 - y^2 ]`

`= x ( x + 5 - y ) ( x + 5 + y )`

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`c) x^2 + x - 6`

`= x^2 + 3x - 2x - 6`

`= x ( x + 3 ) - 2 ( x + 3 )`

`= ( x + 3 ) ( x - 2 )`

_______________________________

`d) 2x^2 + 4x - 16`

`= 2x^2 - 4x + 8x - 16`

`= 2x ( x - 2 ) + 8 ( x - 2 )`

`= ( x - 2 ) ( 2x + 8 )`

a) x2 + xy –x – y = x(x + y) – (x + y) = (x + y)(x -1 ).

b) a2 – b2 + 8a + 16 = (a2 + 8a + 16) – b2 = (a + 4)2 – b2

= (a + 4 – b)(a + 4 + b).

tui chỉ làm dc này thui

\(a,=8x\left(x-y\right)-4\left(x-y\right)\)

\(=\left(x-y\right)\left(8x-4\right)\)

somebody help me 

\(1,2x^2-3x-2\) 

\(=2x^2-4x+x-2\)

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

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

\(2,4x^2-7x-2\)

\(=4x^2-8x+x-2\) 

\(=4x\left(x-2\right)+x-2\)

\(\left(4x+1\right)\left(x-2\right)\)

a: (x^2+x)^2+4x^2+4x-12

=(x^2+x)^2+4(x^2+x)-12

=(x^2+x+6)(x^2+x-2)

=(x^2+x+6)(x+2)(x-1)

b: =(x^2+8x)^2+22(x^2+8x)+105+15

=(x^2+8x)^2+22(x^2+8x)+120

=(x^2+8x+10)(x^2+8x+12)

=(x^2+8x+10)(x+2)(x+6)

c: =8x^2+12x-2x-3

=(2x+3)(4x-1)

a: =(x^2+x)^2+4(x^2+x)-12

=(x^2+x+6)(x^2+x-2)

=(x^2+x+6)(x+2)(x-1)

b: =(x^2+8x)^2+22(x^2+8x)+120

=(x^2+8x+12)(x^2+8x+10)

=(x+2)(x+6)(x^2+8x+10)

c: =8x^2+12x-2x-3

=(2x+3)(4x-1)

a) (x - 1) - (2x - 1) = 9 - x

<=> x - 1 - 2x + 1 = 9 - x

<=> x - 2x + x = 9 + 1 - 1

<=> 0x = 9 (vô lý vì 0x = 0 với mọi x)

Vậy PT vô nghiệm

b) 3 - 4x. (25 - 2x) = 8x²

<=> 3 - 100x + 8x² = 8x²

<=> 3 - 100x = 0

<=> -100x = -3

<=> 100x = 3

\(\Leftrightarrow x=\dfrac{3}{100}\)

Vậy: \(S=\left\{\dfrac{3}{100}\right\}\)

a) (x-1) - (2x-1) = 9-x

<=> x - 1 - 2x + 1= 9-x

<=> -x = 9-x

<=> -x + x = 9 

<=> 0 = 9 ( sai )

Vậy tập nghiệm S ={\(\varnothing\)}

b) 3 - 4x(25 - 2x) = 8x²

<=> 3 - 100x + 8x² = 8x²

<=> 3 = 100x

<=> \(\dfrac{3}{100}\)= x = 0,03

Vập tập nghiệm S ={0,03}

a) 

\(P=\left(x^{14}-9x^{13}\right)-\left(x^{13}-9x^{12}\right)+\left(x^{12}-9x^{11}\right)-...+\left(x^2-9x\right)-\left(x-9\right)+1\)

\(=x^{13}\left(x-9\right)-x^{12}\left(x-9\right)+x^{11}\left(x-9\right)+...+x\left(x-9\right)-\left(x-9\right)+1\)

\(P\left(9\right)=1\)

b)

\(Q=\left(x^{15}-7x^{14}\right)-\left(x^{14}-7x^{13}\right)+\left(x^{13}-7x^{12}\right)-...-\left(x^2-7x\right)+\left(x-7\right)+2\)

\(=x^{14}\left(x-7\right)-x^{13}\left(x-7\right)+x^{12}\left(x-7\right)-...-x\left(x-7\right)+\left(x-7\right)+2\)

\(Q\left(7\right)=2\)