Lời giải:
Ta có:
\(8x^3-18x^2+x+6=8x^2(x-2)-2x(x-2)-3(x-2)\)
\(=(x-2)(8x^2-2x-3)\)
\(=(x-2)[4x(2x+1)-3(2x+1)]\)
\(=(x-2)(2x+1)(4x-3)\)
\(8x^3-18x^2+x+6\)
\(=8x^3-16x^2-2x^2+4x-3x+6\)
\(=\left(8x^3-16x^2\right)-\left(2x^2-4x\right)-\left(3x-6\right)\)
\(=8x^2\left(x-2\right)-2x\left(x-2\right)-3\left(x-2\right)\)
\(=\left(x-2\right)\left(8x^2-2x-3\right)\)
\(=\left(x-2\right)\left(8x^2+4x-6x-3\right)\)
\(=\left(x-2\right)\left[\left(8x^2+4x\right)-\left(6x+3\right)\right]\)
\(=\left(x-2\right)\left[4x\left(2x+1\right)-3\left(2x+1\right)\right]\)
\(=\left(x-2\right)\left(2x+1\right)\left(4x-3\right)\)
8X3-18X2+X+6
=8x3-16x2-2x2+4x-3x+6
= (8x3-16x2)-(2x2-4x)-(3x-6)
=8x2(x-2)-2x(x-2)-3(x-2)
=(x-2)(8x2-2x-3)
=(x-2)(8x2+4x-6x-3)
=(x-2)[4x(2x+1)-3(2x+1)]
=(x-2)(4x-3)(2x+1)
