Question 1114756
This is a bad way to say it:
--
(x+1)=-1 as a zero.
--


Just say, either x+1 is a factor of f; or say that -1 is a zero of f.

<pre>

-1   |   2   -4   -5   1
     |
     |       -2    6   -1
     |__________________________
        2   -6     1    0
</pre>

{{{f(x)=(x+1)(2x^2-6x+1)}}}
and next yhou want to factorize or find zeros of the quadratic factor.


Zeros for the quadratic factor
{{{(6+- sqrt(36-4*2))/4}}}

{{{(6+- sqrt(28))/4}}}

{{{(6+- 2*sqrt(7))/4}}}

{{{highlight((3+- sqrt(7))/2)}}}-------the two other real but irrational roots. (zeros)