Question

Phân tích 3x^2 - 3y^2 - 12xy +12y^2

Answer 1

\(3x^2-3y^2-12xy+12y^2\)

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

Answer 2

\(3x^2-3y^2-12xy+12y^2=3\left(x^2-y^2-4xy+4y^2\right)=3\left\{\left[x^2-4xy+\left(2y\right)^2\right]-y^2\right\}=3\left[\left(x-2y\right)^2-y^2\right]==3\left(x-2y+y\right)\left(x-2y-y\right)=3\left(x-y\right)\left(x-3y\right)\)