a) \(6^2-11x+3\)

\(=6x^2-2x-9x+3\)

\(=\left(6x^2-2x\right)-\left(9x-3\right)\)

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

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

b)\(2x^2+3x-27\)

\(=2x^2-6x+9x-27\)

\(=\left(2x^2-6x\right)+\left(9x-27\right)\)

\(=2x\left(x-3\right)+9\left(x-3\right)\)

\(=\left(2x+9\right)\left(x-3\right)\)

c)\(2x^2-5xy+3y^2\)

\(=2x^2-2xy-3xy+3y^2\)

\(=\left(2x^2-2xy\right)-\left(3xy-3y^2\right)\)

\(=2x\left(x-y\right)-3y\left(x-y\right)\)

\(=\left(2x-3y\right)\left(x-y\right)\)

d)\(2x^2-5xy-3y^2\)

\(=2x^2+xy-6xy-3y^2\)

\(=\left(2x^2+xy\right)-\left(6xy+3y^2\right)\)

\(=x\left(2x+y\right)-3y\left(2x+y\right)\)

\(=\left(x-3y\right)\left(2x+y\right)\)

a) 6x² - 11x + 3

= 6x² - 9x - 2x + 3

= 3x ( 2x - 3 ) - ( 2x - 3 )

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

b ) 2x² + 3x - 27

= 2x² - 6x + 9x - 27

= 2x ( x - 3 ) + 9 ( x - 3 )

= ( x - 3 ) ( 2x + 9 )

c ) 2x² - 5xy - 3y²

= 2x² - 2xy - 3xy - 3y²

= 2x ( x - y ) - 3y ( x - y )

= ( x - y ) ( 2x - 3y )

Ta có: 

a) 6x² - 11x +3 = 2x(3x-1)-3(3x-1)=(2x-3)(3x-1)

b) 2x² +3x - 27= x(2x+9)-3(2x+9)=(x-3)(2x+9)

c) 2x²  -5xy-3y² = 2x(x-3y)+y(x-3y)=(2x+y)(x-3y)

a) 6x² - 11x + 3 = 6x² - 2x - 9x + 3 = 2x(3x - 1) - 3(3x - 1) = (3x - 1)(2x - 3)

b) 2x² + 3x - 27 = 2x² - 6x + 9x - 27 = 2x(x - 3) + 9(x - 3) = (x - 3)(2x + 9)

c) 2x² - 5xy - 3y² = 2x² + xy - 6xy - 3y² = x(2x + y) - 3y(2x + y) = (2x + y)(x - 3y)

6x²-11x+3

<=> 6x² - 2x -9x +3

<=> 2x( 3x -1) - 3(3x-1)

<=> (3x-1)(2x-3)

what ???

d)  \(2x^2-3x-27\)

\(=\left(2x^2+6x\right)-\left(9x+27\right)\)

\(=2x\left(x+3\right)-9\left(x+3\right)\)

\(=\left(2x-9\right)\left(x+3\right)\)

e)  \(2x^2-5xy-3y^2\)

\(=\left(2x^2+xy\right)-\left(6xy+3y^2\right)\)

\(=2x\left(x+y\right)-3y\left(x+y\right)\)

\(=\left(2x-3y\right)\left(x+y\right)\)

1, (x-y)(x-3)

2,(x-y)(x+2)

3,(x+1)(x+5y)

1