Question

Phân tích đa thức thành nhân tử

9a³-13a+6

x⁴-4x³+8x+3

a^3m+2a^2m+a^m

a⁴-9a³+81a-81

Answer 1

\(9a^3-13a+6=\left(9a^3-6a^2\right)+\left(6a^2-4a\right)-\left(9a-6\right)=3a^2\left(3a-2\right)+2a\left(3a-2\right)-3\left(3a-2\right)=\left(3a-2\right)\left(3a^2+2a-3\right)\)

Answer 2

\(x^4-4x^3+8x+3=\left(x^4+x^3\right)-\left(5x^3+5x^2\right)+\left(5x^2+5x\right)+\left(3x+3\right)=x^3\left(x+1\right)-5x^2\left(x+1\right)+5x\left(x+1\right)+3\left(x+1\right)=\left(x+1\right)\left(x^3-5x^2+5x+3\right)=\left(x+1\right)\left[\left(x^3-3x^2\right)-\left(2x^2-6x\right)-\left(x-3\right)\right]=\left(x+1\right)\left(x-3\right)\left(x^2-2x-1\right)\)

Answer 3

\(a^4-9a^3+81a-81\)

\(=\left(a^2-9\right)\left(a^2+9\right)-9a\left(a^2-9\right)\)

\(=\left(a-3\right)\left(a+3\right)\left(a^2-9a+9\right)\)