Question

X^2 - 8x -9

Phân tích đa thức thàh nhân tử .Cần gấp ạ cảm ơn mn nhiều.

Answer 1

\(x^2-8x-9\)

\(=x^2+x-9x-9\)

\(=\left(x^2+x\right)-\left(9x+9\right)\)

\(=x\left(x+1\right)-9\left(x+1\right)\)

\(=\left(x-9\right)\left(x+1\right)\)

Answer 2

\(x^2-8x-9\)

\(=x^2+x-9x-9\)

\(=\left(x^2+x\right)-\left(9x+9\right)\)

\(=x\left(x+1\right)-9\left(x+1\right)\)

\(=\left(x-9\right)\left(x+1\right)\)