Question

phan tich da thuc thanh nhan tu

\(2x^3-x^2+5x+3\)

Answer 1

$ 2x^3 - x^2 + 5x + 3 \\ = 2x^3 + x^2 - 2x^2 - x + 6x + 3 \\ = x^2(2x + 1) - x(2x + 1) + 3(2x + 1) \\ = (2x + 1)(x^2 - x + 3) $

Answer 2

\(2x^3-x^2+5x+3\)

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

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

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

Vì \(x^2-x+3=\left(x-\dfrac{1}{2}\right)^2-\dfrac{1}{4}+3>0\)

Nên ​​

\(2x^3-x^2+5x+3=\left(2x+1\right)\left(x^2-x+3\right)\)