Question

Tìm x biết:

2x³+x²-8x-4

Answer 1

\(2x^3+x^2-8x-4\\ =\left(2x^3+x^2\right)-\left(8x+4\right)\\ =x^2\left(2x+1\right)-4\left(2x+1\right)\\ =\left(x^2-4\right)\left(2x+1\right)\\ =\left(x-2\right)\left(x+2\right)\left(2x+1\right)\)

Answer 2

\(2x^3+x^2-8x-4=x^2\left(2x-1\right)-4\left(2x-1\right)=\left(x-2\right)\left(x+2\right)\left(2x-1\right)\)

Answer 3

\(2x^3+x^2-8x-4\)

\(=x^2\left(2x+1\right)-4\left(2x+1\right)\)

\(=\left(2x+1\right)\cdot\left(x^2-4\right)\)

\(=\left(x-2\right)\left(x+2\right)\cdot\left(2x+1\right)\)