Question

 

 1. Phân tích da thức thành nhân tử5x²-10xy+5y²-20z²   

Answer 1

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

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

\(=5\left[\left(x-y\right)^2-4z^2\right]\)

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

Answer 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)]

chúc bn hc tốt

Answer 3

Ta có: \(5x^2-10xy+5y^2-20z^2\)

\(=5\cdot\left(x^2-2xy+y^2-4z^2\right)\)

\(=5\cdot\left[\left(x^2-2xy+y^2\right)-\left(2z\right)^2\right]\)

\(=5\cdot\left[\left(x-y\right)^2-\left(2z\right)^2\right]\)

\(=5\cdot\left(x-y-2z\right)\left(x-y+2z\right)\)