Question 1013303
f(x)=x^3 -5x^2 -9x+45 
rational zeros are +/- 1,3,5,9,15,45
1===-5====-9====45; try -3.  Bring down the 1, multiply by -3 and add that to -5 to get -8.  Then
1===-8------15------45 ;;;;;;;;;;;multiply that by -3 and add to -9 to get 15.  Multiply that by -3 to get 
(x+3) is a factor.;;;;;;;;;;;;;;;;;;;;;;;-45, and that makes 0.
(x^2-8x+15) is a factor
(x-5)(x-3)
The roots are {-3,5,3}
{{{graph(300,200,-10,10,-10,10,x^3 -5x^2 -9x+45 )}}}