= x^2 - 7xy + 10y^2
= x^2 - 2xy -5xy + 10y^2
= x( x - 2y ) - 5y( x - 2y )
= ( x - 2y )( x - 5y )

x² – 7xy + 10y2 

= x² – 2xy – 5xy + 10y²

= x(x – 2y) – 5y(x – 2y)

= (x – 2y)(x – 5y)

\(a,x^2\left(x-2\right)-4x+8\\ =\left(x^2-4\right)\left(x-2\right)\\ =\left(x-2\right)^2\left(x+2\right)\\ b,x^2+7xy+10y^2\\ =x^2+2xy+5xy+10y^2\\ =x\left(x+2y\right)+5y\left(x+2y\right)\\ =\left(x+5y\right)\left(x+2y\right)\)

x^2 - 7xy + 10y^2 
= (x^2 - 2xy) - (5xy - 10y^2) 
= x(x - 2y) - 5y( x - 2y) 
= (x - 5y)(x - 2y) 

mik mới học lớp 7 thôi!

Ta có : x³ - 3x² + 1 - 3x

= x³ - 2x² - x - (x² - 2x - 1) 

= x(x² - 2x - 1) - (x² - 2x - 1) 

= (x² - 2x - 1) (x - 1) 

a)  \(x^2+6x+8\)

\(=\left(x^2-2x\right)-4x+8\)

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

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

b) \(x^2-7xy+10y^2\)

\(=x^2-2xy-5xy+10y^2\)

\(=x\left(x-2y\right)-5y\left(x-2y\right)\)

\(=\left(x-2y\right)\left(x-5y\right)\)

a) x² - 6x + 8

= x² -2x - 4x +8

= x( x-2) -4( x-2)

= ( x-2)(x-4)

a/ \(x^2-6x+8=x^2-2x-4x+8\) \(8\) \(=x\left(x-2\right)-4\left(x-2\right)\) \(=\left(x-4\right)\left(x-2\right)\)

b/ \(x^2-7xy+10y^2\) \(=x^2-2xy-5xy+10y^2\) \(=x\left(x-2y\right)-5y\left(x-2y\right)\) \(=\left(x-5y\right)\left(x-2y\right)\)

= (x² - 2xy) - ( 5xy - 10y² )

=x(x-2y) - 5y( x-2y)

= (x-5y)(x-2y)

  x² - 7xy + 10y²

= x² - 2xy - 5xy + 10y²

= ( x² - 2xy ) - (5xy - 10y² )

= x ( x - 2y ) - 5y ( x-2y)

= ( x-2y ) ( x-5y )

\(x^2-xy-10x+10y\)

\(=x\left(x-y\right)-10\left(x-y\right)\)

\(=\left(x-y\right)\left(x-10\right)\)

a. x² + 7xy + 10y²

= x² + 2xy + 5xy + 10y²

= x.(x + 2y) + 5y.(x + 2y)

= (x + 2y).(x + 5y)

b. x² - 6xy + 5y²

= x² - xy - 5xy + 5y²

= x.(x - y) - 5y.(x - y)

= (x - y).(x - 5y)