Question

PLEASE I NEED HELP SO I CAN MOVE ON WITH MY HW
Can you find the zeroes of this function using synthetic division
f(x)=2x^3-10x^2-71x-9 ; 9 (9 being the zero given)


I can do the synthetic but I can do th ac/b chart because it ends up 2/8 and that doesn't work

Answer 1

At the 2/8 part, just use the quadratic formula.  If you use it, you should get the other two zeroes:

$-4+\frac{\sqrt{14}}{2} \\ -4-\frac{\sqrt{14}}{2}$