ta có :\(5x^2-10xy+5y^2-20z^2=5\left(x^2-2xy+y^2-4z^2\right)=5\left(\left(x-y\right)^2-\left(2z\right)^2\right)=5\left(x-y-2z\right)\left(x-y+2z\right)\)

5x² - 10xy + 5y² - 20z²

=5(x² - 2xy + y² - 4z²)

= 5[ (x² - 2xy + y²) - (2z)²]

= 5[(x-y)² - (2z)²]

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

5x²-10xy+5y²-20z²

=5(x²-2xy+y²-4z²)

=5[(x-y)²-(2z)²]

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

a) (x^2+2xy+y^2)-9=(x+y)^2-9=(x+y-3)(x+y+3)

b) 5(x^2-2xy+y^2-4z^2)=5[(x-y)^2-4z^2]=5[(x-y-2z)(x-y+2z)

c)x^2-2x-5x+10=x(x-2)-5(x-2)=(x-5)(x-2)

d)2x^2-4x-3x+6=2x(x-2)-3(x-2)=(2x-3)(x-2)

5x² - 10xy + 5y² - 20z² 

= 5(x² - 2xy + y² - 4z²)

=  5[(x² - 2xy + y²) - 4z²]

= 5 [(x - y)² - (2z)²]

= 5 (x - y - 2z) (x - y +2z)

5x² - 10xy + 5y² - 20z²

= 5.(x² - 2xy + y² - 4z²)

= 5.[(x² - 2xy + y²) - (2z)²]

= 5.[(x - y)² - (2z)²]

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

x².(1 - x²) - 4 + 4x²

= x².(1 - x²) - 4.(1 - x²)

= (1 - x²).(x² - 4)

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

5x² - 10xy + 5y² - 20z²

= 5.(x² - 2xy + y² - 4z²)

= 5.[(x² - 2xy + y²) - (2z)²]

= 5.[(x - y)² - (2z)²]

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

x².(1 - x²) - 4 + 4x²

= x².(1 - x²) - 4.(1 - x²)

= (1 - x²).(x² - 4)

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

a) phân tích đc \(\left(x+y+2z\right)\left(x+y-2z\right)\)

b) phân tích đc \(\left(1-x^2\right)\left(x-2\right)\left(x+2\right)\)

k chị nha

5x\(^2\)- 10xy +5x\(^2\)-20z\(^2\)
= 5(x\(^2\)-2xy+x\(^2\)-4z\(^2\))
= 5(2x\(^2\)-2xy-4z\(^2\))
 

5^2-10xy+5x^2-20z^2

=5(x^2-2xy+y^2-4z^2)

=5((x-y)^2-4z^2)

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

d)

x³ + 2x²y+ xy² - 9x 

=x*(x²+2xy+y² -9)

=x*[ (x+y)² -3² ​​] 

=x * (x+y-3) * (x+y-3)