Question

Find all the zeros of the polynomial f (x) close is equal to x cube + 13 x square + 32 X + 20 if one of its zero is -2

Answer 1

x^3+13x^2+32x+20=0 can be written as

1. (x+1)(x^2+12x+20)=0
2. (x+1)(x^2+10x+2x+20)=0
3. (x+1)(x(x+10)+2(x+10))=0
4. (x+1)((x+10)(x+2))=0
5. x+1=0,x+10=0,x+2=0
6. x=-1,x=-10,x=-2