Question

tách tam thức bậc 2 hoặc bậc 3 (lớp 8): x^3 + x + 2

Answer 1

\(x^3+x+2\)

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

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

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

Answer 2

\(x^3+x+2\)

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

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

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

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

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