Question

Phân tích đa thức thành nhân tử

1, x-xy+ y+y²

2, 3x-6y+xy-2y​²

3, x²+2x-y²+1

4, x²+2x+1-16y²

5, x²​-y²+5x+5y

6,25- x²+2xy-y²

7, x³+2x²y+xy​²-9x

8, x³+2x²-6x-27

Answer 1

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

3: \(=x^2+2x+1-y^2\)

\(=\left(x+1\right)^2-y^2\)

\(=\left(x+1+y\right)\left(x+1-y\right)\)

4: \(x^2+2x+1-16y^2\)

\(=\left(x+1\right)^2-16y^2\)

\(=\left(x+1+4y\right)\left(x+1-4y\right)\)

5: \(x^2-y^2+5x+5y\)

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

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

6: \(=25-\left(x^2-2xy+y^2\right)\)

\(=25-\left(x-y\right)^2\)

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