Question

(x²-9):(x+3)

 

Answer 1

\(\dfrac{x^2-9}{x+3}=\dfrac{\left(x-3\right)\left(x+3\right)}{x+3}=x-3\)dk x khac -3 

Answer 2

\(\left(x^2-9\right):\left(x+3\right)\)

\(=\dfrac{x^2-9}{x+3}\)

\(=\dfrac{x^2-3x+3x-9}{x+3}\)

\(=\dfrac{x\left(x-3\right)+3\left(x-3\right)}{\left(x+3\right)}\)

\(=\dfrac{\left(x+3\right)\left(x-3\right)}{x+3}\)

\(=x-3\)