Question

phân tích đa thức thành nhân tử : 9x4 + 36x3 + 29x2 - 14x 

Answer 1

\(9x^4+36x^3+29x^2-14x\)

\(=x\left(9x^3+36x^2+29x-14\right)\)

\(=x\left(9x^3+18x^2+18x^2+36x-7x-14\right)\)

\(=x\left[9x^2\left(x+2\right)+18x\left(x+2\right)-7\left(x+2\right)\right]\)

\(=x\left(x+2\right)\left(9x^2+18x-7\right)\)

\(=x\left(x+2\right)\left(9x^2-3x+21x-7\right)\)

\(=x\left(x+2\right)\left[3x\left(3x-1\right)+7\left(3x-1\right)\right]\)

\(=x\left(x+2\right)\left(3x+7\right)\left(3x-1\right)\)