Question

Phan tích đa thức thành nhân tử:

a) 3x+6y-12xy           b) x²-2x+xy-2y

c) 5x²-5z²                  d) x²-9+2x(x-3)

Answer 1

c: =5(x-z)(x+z)

Answer 2

a/ \(3x+6y-12xy\)

\(=3\left(x+2y-4xy\right)\)

b/ \(x^2-2x+xy-2y\)

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

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

c/ \(5x^2-5z^2\)

\(=5\left(x^2-z^2\right)\)

\(=5\left(x-z\right)\left(x+z\right)\)

d/ \(x^2-9+2x\left(x-3\right)\)

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

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

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

Answer 3

a) 3x+6y-12xy

=3(x+2y-4xy)

b)x²-2x+xy-2y=-2x-2y+(x²+xy)=-2(x+y)+x(x+y)=(x+y)(-2+x)

c)5x²-5z²=5(x²-z²)=5(x-z)(x+z)

d)x²-9+2x(x-3)=(x-3)(x+3)+2x(x-3)=(-3)((x+3)+2x)

 

 

 

 

Answer 4