factorise, $x^3-13x^2+32x+20$

2.3k Views Asked by Bumbble Comm At 16 Apr 2026 - 11:27

Let, $f(x)=x^3-13x^2+32x+20$

$f(x)=x(x^2-13x+30)+2x+20$

$f(x)=x(x-3)(x-10)+2x+20$

$f(-1)\lt 0$, $f(0)\gt 0$, which shows there is a root between $x=-1$ and $x=0$

$f(4)\gt 0$, $f(5)\lt 0$, which shows there is a root between $x=4$ and $x=5$

$f(9)\lt 0$, $f(10)\gt 0$, which shows there is a root between $x=9$ and $x=10$