Question

Phân tích A=x^2+x-6 thành nhân tử theo 3 cách

Answer 1

1:\(x^2+x-6=x^2+3x-2x-6=x\left(x+3\right)-2\left(x+3\right)=\left(x-2\right)\left(x+3\right)\)

2:\(x^2+x-6=x^2-2x+3x-6=x\left(x-2\right)+3\left(x-2\right)=\left(x+3\right)\left(x-2\right)\)

3:\(x^2+x-6=x^2+x+\frac{1}{4}-\frac{25}{4}=\left(x+\frac{1}{2}\right)^2-\left(\frac{5}{2}\right)^2=\left(x+\frac{1}{2}-\frac{5}{2}\right)\left(x+\frac{1}{2}+\frac{5}{2}\right)=\left(x-2\right)\left(x+3\right)\)

Answer 2

\(A=x^2+x-6\)

\(\Rightarrow A=x^2+3x-2x-6\)

\(\Rightarrow A=x\left(x+3\right)-2.\left(x+3\right)\)

\(\Rightarrow A=\left(x-2\right).\left(x+3\right)\)

P/s: Mình không chắc lắm vì mình mới làm quen với dạng này .