a: =(x+y)(x-3)

b: =x(x^2-2x+1+4y^2)

bạn viết lại đề đi, có số mũ, xuống dòng chứ thế này ai mà giải được

1: =(16x^2-8x+1)-y^2

=(4x-1)^2-y^2

=(4x-1-y)(4x-1+y)

2: =(x^2-2xy+y^2)-z^2

=(x-y)^2-z^2

=(x-y-z)(x-y+z)

3: =(x^2+4xy+4y^2)-16

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

=(x+2y-4)(x+2y+4)

4: =(x^2-4xy+4y^2)-16

=(x-2y)^2-4^2

=(x-2y-4)(x-2y+4)

= x²-4xy +4y²-y²

=(x-2y)² -y²

=(x-2y+y)(x-2y-y)

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

tích nhoa

a) x⁴ - x⁵ = x⁴( x - 1 )

b) -8x²y² - 12xy³ - 4xy²

= -4xy( 2xy + 3y² + y )

c) ( x - y )³ - x³ + y³

= x³ - 3x²y + 3xy² - y³ - x³ + y³

= 3xy² - 3x²y

= 3xy( y - x )

\(x^2+5x+6\)

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

\(=x.\left(x+3\right)+2.\left(x+3\right)=\left(x+3\right).\left(x+2\right)\)

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

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

2, \(x^3-7x+6=x^3-x^2+x^2-x-6x+6\)

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

3, \(x^2+4xy+3y^2=x^2+4xy+4y^2-y^2\)

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

4, \(x^2-8x+12=x^2-2x-6x+12\)

\(=x\left(x-2\right)-6\left(x-2\right)=\left(x-6\right)\left(x-2\right)\)

Trả lời:

1, x⁴ - 5x² + 4 

= x⁴ - 4x² - x² + 4

= ( x⁴ - 4x² ) - ( x² - 4 )

= x² ( x² - 4 ) - ( x² - 4 )

= ( x² - 4 )( x² - 1 )

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

2, x³ - 7x + 6 

= x³ - 7x + 6 + x² - x²

= x³ - 6x - x + 6 + x² - x²

= ( x³ - x² ) + ( x² - x ) - ( 6x - 6 )

= x² ( x - 1 ) + x ( x - 1 ) - 6 ( x - 1 )

= ( x - 1 )( x² + x - 6 )

= ( x - 1 )( x² - 2x + 3x - 6 )

= ( x - 1 )[ x ( x - 2 ) + 3 ( x - 2 ) ]

= ( x - 1 )( x + 3 )( x - 2 )

3, x² + 4xy + 3y²

= x² + 4xy + 4y² - y²

= ( x² + 4xy + 4y² ) - y²

= ( x + 2y )² - y²

= ( x + 2y - y )( x + 2y + y )

= ( x + y )( x + 3y )

4, x² - 8x + 12

= x² - 6x - 2x + 12

= x ( x - 6 ) - 2 ( x - 6 )

= ( x - 6 )( x - 2 )